Techniques for Reduced Order Modeling of Aeroelastic Structures With Deforming Grids
Reduced order modeling (ROM) seeks to make the modeling of aeroelastic behavior practical by reducing computation time for design codes. Deforming grids are often used in aeroelastic problems to account for the deformation of the structure. Proper Orthogonal Decomposition (POD/ROM) is a ROM technique that operates in an index-space for computations, not accounting for changes in grid dynamics, and must be modified to reflect grid deformation properly. As a POD/ROM is developed, fluid dynamics modes are created based on the index relationship between grid points. The modes are then used to recreate the full-order solution. When the relationship between the grid point locations and the index space changes, the created modes are no longer valid because the new grid dynamics are not captured accurately. To investigate and account for the effects of grid deformation on POD/ROM, a new algorithm is developed that incorporates modifications to the usual formulation.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Measurement of Human Pilot Dynamic Characteristics in Flight Simulation
Fast Fourier Transform (FFT) and Least Square Error (LSE) estimation techniques were applied to the problem of identifying pilot-vehicle dynamic characteristics in flight simulation. A brief investigation of the effects of noise, input bandwidth and system delay upon the FFT and LSE techniques was undertaken using synthetic data. Data from a piloted simulation conducted at NASA Ames Research Center was then analyzed. The simulation was performed in the NASA Ames Research Center Variable Stability CH-47B helicopter operating in fixed-basis simulator mode. The piloting task consisted of maintaining the simulated vehicle over a moving hover pad whose motion was described by a random-appearing sum of sinusoids. The two test subjects used a head-down, color cathode ray tube (CRT) display for guidance and control information. Test configurations differed in the number of axes being controlled by the pilot (longitudinal only versus longitudinal and lateral), and in the presence or absence of an important display indicator called an 'acceleration ball'. A number of different pilot-vehicle transfer functions were measured, and where appropriate, qualitatively compared with theoretical pilot- vehicle models. Some indirect evidence suggesting pursuit behavior on the part of the test subjects is discussed.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
On the Calculation of Steady Boundary Layers for Continuous Suction, With Discontinuously Variable Suction Velocity
Almost all solutions, so far known, of the problem of exact calculation of the velocity distribution in a boundary layer under the influence of continuous suction pertain to the class of "similar" solutions. One deals, therefore, with individual particular integrals of the boundary-layer equations under special boundary conditions. Compilations may be found, for instance, in H. Schlichting or E. J. Watson. If one disregards the reports using the so-called Pohlhausen methods, thus not yielding rigorous solutions of the boundary-layer equations, there exist only very few investigations which deal with the suction boundary layer for arbitrarily prescribable boundary conditions. Here belongs, for instance, the paper by R. Iglisch which treats the onset of the boundary-layer flow on a flat plate in longitudinal flow with homogeneous suction. On the other hand the case of merely piecewise suction for otherwise impermeable wall which is of extreme interest for practical cases - has so far not been rigorously investigated. The main reason probably is that at the beginning and at the end of every suction region the value of the v velocity component at the wall becomes discontinuous so that all customary calculation methods fail there. In the present report, we shall develop a method, on the example of a jumplike start of suction for arbitrary external pressure distribution and arbitrary suction law - a method which permits the exact calculation of the rapid variations of the velocity distribution (according to boundary-layer theory) near arbitrary flow discontinuities of the kind mentioned.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Flight Test Analysis of the Forces and Moments Imparted on a B737-100 Airplane During Wake Vortex Encounters
Aircraft travel has become a major form of transportation. Several of our major airports are operating near their capacity limit, increasing congestion and delays for travelers. As a result, the National Aeronautics and Space Administration (NASA) has been working in conjunction with the Federal Aviation Administration (FAA), airline operators, and the airline industry to increase airport capacity without sacrificing public safety. One solution to the problem is to increase the number of airports and build new. runways; yet, this solution is becoming increasingly difficult due to limited space. A better solution is to increase the production per runway. This solution increases the possibility that one aircraft will encounter the trailing wake of another aircraft. Hazardous wake vortex encounters occur when an aircraft encounters the wake produced by a heavier aircraft. This heavy-load aircraft produces high-intensity wake turbulence that redistributes the aerodynamic loads of trailing smaller aircraft. This situation is particularly hazardous for smaller aircraft during takeoffs and landings. In order to gain a better understanding of the wake-vortex/aircraft encounter phenomena, NASA Langley Research Center conducted a series of flight tests from 1995 through 1997. These tests were designed to gather data for the development a wake encounter and wake-measurement data set with the accompanying atmospheric state information. This data set is being compiled into a database that can be used by wake vortex researchers to compare with experimental and computational results. The purpose of this research is to derive and implement a procedure for calculating the wake-vortex/aircraft interaction portion of that database by using the data recorded during those flight tests. There were three objectives to this research. Initially, the wake-induced forces and moments from each flight were analyzed based on varying flap deflection angles.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
The UAV Continuous Coverage Problem
The purpose of this research is to develop a method to find an optimal UAV cyclic schedule to provide maximum coverage over a target area to support an ISR mission. The goal is to reach continuous coverage. UAV continuous coverage of a target area is crucial for the success of an ISR mission. Even the smallest coverage gap may jeopardize the success of the mission. Ideally it is desirable to obtain continuous coverage of a target area but the stochastic nature of the problem makes continuous coverage without gaps unlikely. However, it is still possible to obtain a high coverage rate. Coverage gaps may occur at handoff from one UAV to another. We first study a deterministic model with identical UAVs and derive the minimum number of required UAVs to ensure continuous coverage. Continuous coverage is possible only in the deterministic setting. The model provides valuable insights on the parameters driving the UAV performance coverage. It is shown that the loitering and the roundtrip times are the most impacting parameters driving the performance coverage of the UAVs. It is proved that the number of UAVs is an increasing function of the roundtrip time and a decreasing function of the loitering time.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Computational Modeling of the Dielectric Barrier Discharge Device for Aeronautical Applications
Dielectric Barrier Discharge (DBD) type devices, when used as plasma actuators, have shown significant promise for use in many aeronautical applications. Experimentally, DBD actuator devices have been shown to induce motion in initially still air, and to cause re-attachment of air flow over a wing surface at a high angle of attack. This thesis explores the numerical simulation of the DBD device in both a 1D and 2D environment. Using well established fluid equation techniques, along with the appropriate approximations for the regime under which these devices will be operating, computational results for various conditions and geometries are explored. In order to validate the code, results are compared to analytic or experimental data whenever possible, or matched with other similar numeric simulations to help establish the accuracy of the code. Solutions to Poisson's equation for the potential, electron and ion continuity equations, and the electron energy equation are solved semi-implicitly in a sequential manner.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
An Analysis of Aircraft Handling Quality Data Obtained From Boundary Avoidance Tracking Flight Test Techniques
Cooper-Harper ratings (CHRs) have been used to describe and compare aircraft handling qualities for over 40 years, but are by their very nature, subjective. The subjective and sometimes ambiguous results obtained from qualitative handling quality ratings are inconsistent with the rest of the flight test process, where quantifiable results followed by statistical analysis are the norm. This thesis presents a method for obtaining accurate and consistent flight test data that quantifies the handling qualities of a specific aircraft. The method is demonstrated using both pilot-in-the-loop simulations and flight tests with the NF-16D Variable-Stability In-Flight Simulator Test Aircraft (VISTA). Boundary Avoidance Tracking (BAT), introduced in 2004 by Mr. William Gray III, a test pilot at the US Air Force Test Pilot School (TPS), is used here to provide a novel approach for forcing an increase in pilot workload and tracking performance in order to assess an aircraft's handling qualities. By utilizing BAT with shrinking desired performance boundaries on a point tracking task, pilots are forced to their maximum performance (i.e. minimum error) on the tracking task.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Development of Cursor-on-Target Control for Semi-Autonomous Unmanned Aircraft Systems
The research presented in this thesis focuses on developing, demonstrating, and evaluating the concept of a Cursor-on-Target control system for semi-autonomous unmanned aircraft systems. The Department of Defense has mapped out a strategy in which unmanned aircraft systems will increasingly replace piloted aircraft. During most phases of flight autonomous unmanned aircraft control reduces operator workload, however, real-time information exchange often requires an operator to relay decision changes to the unmanned aircraft. The goal of this research is to develop a preliminary Cursor-on-Target control system to enable the operator to guide the unmanned aircraft with minimal workload during high task phases of flight and then evaluate the operator's ability to conduct the mission using that control system. For this research, the problem of Cursor-on-Target control design has multiple components. Initially, a Cursor-on-Target controller is developed in Simulink. Then, this controller is integrated into the Aviator Visual Design Simulator to develop an operator-in-the-loop test platform. Finally, a ground target is simulated and tracked to validate the Cursor-on-Target controller. The Cursor-on-Target control system is then evaluated using a proposed operator rating scale.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Non-Destructive Evaluation of Aerospace Composites
Five methods of non-destructive material evaluation (NDE) were used to inspect various forms of damage commonly found in aerospace fiberglass composites: voids, edge and sub-surface delaminations, surface burning, and cracking. The images produced by X-ray, X-ray Computed Tomography, terahertz (THz) imaging, ultrasound, and flash IR thermography were analyzed for the detection of defects. Test results and analysis of each NDE method's capabilities provide a comparison study of conventional techniques versus the emerging technology of THz imaging for the non-destructive evaluation of aerospace composite materials. A comparison guide to the five methods' damage detection effectiveness for fiberglass composites is provided by defect type.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Evolving Self-Organized Behavior for Homogeneous and Heterogeneous UAV or UCAV Swarms
This research designs an off-line evolutionary system to create multi-UAV behavior capable of searching for and attacking targets. The design for this behav- ior system assumes the UAVs have no apriori knowledge about undetected targets, UAVs, or the environment. In addition, the system does not rely upon global com- munications. WIth regard to the behavior design and approach, self-organization is a potential solution since exemplar systems relying upon it tend to be exceptionally robust, scaleable, and -exible. The UAV behavior, evolved with a genetic algorithm, relies upon a behavior archetype architecture. This design allows the system to evolve a small set of behaviors that are selected based upon particular sense inputs to the UAVs. The sense inputs summarize observable characteristics of each UAVs environmental representation such as the density of sensed UAVs and a simple target associated pheromone.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Minimizing Losses in a Space Laser Power Beaming System
A mathematical model is developed to track the amount of power delivered in a wireless laser power beaming system. In a wireless system the power proceeds through several different stages before being delivered to a payload for use. Each of these stages results in power losses that are thoroughly examined, allowing for the calculation of the likely amount of power delivered. Adjusting variable factors within the model allows for the optimization of the system for a specific task. The model shows that an optimized wireless power transfer system can deliver enough power to meet the space experiment objectives. For example to power a Hall-Effect Thruster a laser, photovoltaic cells, satellite power distribution model, and batteries all impact the amount of power delivered. Careful selection of all of these components will allow the laser to power the thruster and the model provides how much power is transferred. Knowledge of the power requirements for the payload further allows the model to determine how long it will be able to operate the payload with the power provided. This model will allow system engineers to answer important design questions about the selection of components to ensure that the end product delivers maximum power.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings
Multilayer insulation (MLI) has been shown to be the best performing cryogenic insulation system at high vacuum (less that 10 (exp 3) torr), and is widely used on spaceflight vehicles. Over the past 50 years, many investigations into MLI have yielded a general understanding of the many variables that are associated with MLI. MLI has been shown to be a function of variables such as warm boundary temperature, the number of reflector layers, and the spacer material in between reflectors, the interstitial gas pressure and the interstitial gas. Since the conduction between reflectors increases with the thickness of the spacer material, yet the radiation heat transfer is inversely proportional to the number of layers, it stands to reason that the thermal performance of MLI is a function of the number of layers per thickness, or layer density. Empirical equations that were derived based on some of the early tests showed that the conduction term was proportional to the layer density to a power. This power depended on the material combination and was determined by empirical test data. Many authors have graphically shown such optimal layer density, but none have provided any data at such low densities, or any method of determining this density. Keller, Cunnington, and Glassford showed MLI thermal performance as a function of layer density of high layer densities, but they didn't show a minimal layer density or any data below the supposed optimal layer density. However, it was recently discovered that by manipulating the derived empirical equations and taking a derivative with respect to layer density yields a solution for on optimal layer density. Various manufacturers have begun manufacturing MLI at densities below the optimal density. They began this based on the theory that increasing the distance between layers lowered the conductive heat transfer and they had no limitations on volume. By modifying the circumference of these blankets, the layer density can easily be variThis work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Investigation of Navier-Stokes Code Verification and Design Optimization
With rapid progress made in employing computational techniques for various complex Navier-Stokes fluid flow problems, design optimization problems traditionally based on empirical formulations and experiments are now being addressed with the aid of computational fluid dynamics (CFD). To be able to carry out an effective CFD-based optimization study, it is essential that the uncertainty and appropriate confidence limits of the CFD solutions be quantified over the chosen design space. The present dissertation investigates the issues related to code verification, surrogate model-based optimization and sensitivity evaluation. For Navier-Stokes (NS) CFD code verification a least square extrapolation (LSE) method is assessed. This method projects numerically computed NS solutions from multiple, coarser base grids onto a freer grid and improves solution accuracy by minimizing the residual of the discretized NS equations over the projected grid. In this dissertation, the finite volume (FV) formulation is focused on. The interplay between the xi concepts and the outcome of LSE, and the effects of solution gradients and singularities, nonlinear physics, and coupling of flow variables on the effectiveness of LSE are investigated. A CFD-based design optimization of a single element liquid rocket injector is conducted with surrogate models developed using response surface methodology (RSM) based on CFD solutions. The computational model consists of the NS equations, finite rate chemistry, and the k-6 turbulence closure. With the aid of these surrogate models, sensitivity and trade-off analyses are carried out for the injector design whose geometry (hydrogen flow angle, hydrogen and oxygen flow areas and oxygen post tip thickness) is optimized to attain desirable goals in performance (combustion length) and life/survivability (the maximum temperatures on the oxidizer post tip and injector face and a combustion chamber wall temperature).This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Dual Channel Matched Filtering and Space-Time Adaptive Processing
We propose a dual channel matched filtering system that addresses two key challenges in the practical implementation of a single channel matched filtering system: secondary data support and computational cost. We derive an exact expression of the dual channel normalized signal-to-interference plus noise ratio (SINR) in terms of random variables with known distributions and approximate expressions of the mean and variance of the normalized SINR. Using these approximate expressions, we demonstrated that the dual channel system requires half the secondary data to achieve nearly the same SINR performance as an equivalent single channel system. With the dual channel system, two reduced dimension weight vectors are used in place of the larger single channel weight vector, offering the potential reduction in computational cost. The key to the dual channel system is the efficient block diagonalization of the interference plus noise correlation matrix with a fixed transformation.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Technology Transfer Programs
With a limited research and defense budget, cost effective methods of meeting security objectives are crucial. An exploratory investigation of Air Force (AF) technology transfer programs will be addressed in this paper. These programs incorporate dual-use opportunities within their portfolio. There will be a description and discussion of the following technology transfer programs: Small Business Innovation Research (SBIR), Small Business Technology Transfer (STTR), Dual-Use Science and Technology (DUS and T), Technology Transfer (T2), and Independent Research and Development (IR and D). In addition, the description, focus, and requirements of the following technology transfer agreement mechanisms will be discussed: Cooperative Research and Development Agreement (CRADA), Educational Partnership Agreement (EPA), Commercial Test Agreement (CTA), Patent License Agreement (PLA), Technology Investment Agreement (TIA), and Partnership Intermediary Agreement (PIA). A benefit of the technology transfer programs is their enhancement to both U.S. security and competitiveness through investment in dual-use technology This research used a mixed method strategy to collect data, which incorporated data from previous literature on technology transfer, current program data, and semi-structured interviews that included both open and closed ended questions. This method allowed the researcher to converge on the broad results in order to focus on detailed views from the interviewees as well as clarify qualitative data. The findings from this research suggest similarities and differences exist within the technology transfer programs and their agreement mechanisms. Such as project and funding size, as well as scope, and benefits. Finally, the interview process highlighted areas within technology transfer which can be improved.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Aerodynamic Analysis of Lattice Grid Fins in Transonic Flow
Lattice grid fins have been studied for missile tail control for several years. A lattice grid fin can be described as an unconventional missile control surface comprised of an outer frame supported by an inner lattice grid of lifting surfaces. This unconventional fin design offers favorable lift characteristics at high angle of attack as well as almost zero hinge moments allowing the use of small and light actuators. In addition, they promise good storability for potential tube-launched and internal carriage dispenser-launched applications. The drawback for the lattice grid fins is the high drag and potentially poor radar cross section performance produced by this unconventional control surface configuration. Current research at the United State Air Force's Aeroballistic Research Facility (ARF) at Eglin Air Force Base in Florida has indicated there is a critical transonic Mach number where normal shock waves are believed to be present within some of the grid cells. At this particular Mach number, there is a dynamic instability with severe variations of the pitch moment coefficient. A computational fluid dynamics (CFD) study was conducted to investigate these findings and elucidate the flowfield in the grid fin region. The missile model was numerically modeled in Gridgen and computational tests were run in Fluent. Finally, another fin configuration was developed that produced less drag and similar dynamic stability than the other lattice grid fin configurations tested.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Sizing Analysis for Aircraft Utilizing Hybrid-Electric Propulsion Systems
Current conceptual aircraft design methods use historical data to predict and evaluate the size and weight of new aircraft. These traditional design methods have been ineffective to accurately predict the weight or physical dimensions of aircraft utilizing unique propulsion systems. The mild hybrid-electric propulsion system represents a unique design that has potential to improve fuel efficiency and reduce harmful emissions. Hybrid-electric systems take advantage of both reliable electric power and the long range/endurance capabilities of internal combustion engines. Desirable applications include general aviation single-engine aircraft and remotely-piloted aircraft. To demonstrate the advantages of mild hybrid-electric propulsion, a conceptual design code was created that modified conventional methods. Using several case studies, the mild hybrid conceptual design tool verified potential fuel savings for general aviation aircraft and expanded mission capability for remotely-piloted aircraft.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Experimental Investigation of Oblique Wing Aerodynamics at Low Speed
In an effort to increase the range of missiles and guided bombs, the USAF is looking at options for new wing configurations. One such configuration being considered is oblique wings. An oblique wing is a wing that pivots about a point on the aircraft fuselage thereby having one side swept forward and the other swept aft. Additional interest is looking at a wing only configuration that also rotates with one wing tip forward of the other. Studies have shown that this configuration can provide less drag for a given lift at both supersonic cruise and subsonic loiter conditions. This experiment focused on the low speed performance of a missile model with an oblique wing. The wing was tested at seven different sweep angles and at two different speeds. In order to simulate the missile dropping from an aircraft the model was inverted over a stationary ground plane in the tunnel and tested at the same wing obliquity angles. Stalling was found at certain conditions including sweep angles of 0, 15, and 30 deg. The ground plane was shown to result in an increase in lift as well as an increase in drag. The ground plane was also shown to add more longitudinal stability, thus making the missile better performing when dropped from an aircraft.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
System Identification of an on Orbit Spacecraft's Antenna Dynamics
The research presented here is a follow on to previous efforts [Pachter, Barba, 2007] in which a tight control loop was designed to meet performance specifications while minimizing the control gains of a spacecraft mounted flexible antenna. Emphasis is now shifted to system identification in order to increase nominal plant knowledge, estimate plant uncertainty bounds, as well as determine the disturbance band. Knowledge of the plant dynamics along with the corresponding uncertainty bounds will provide for the design of a control system which meets the specifications (tracking and disturbance rejection) while at the same time employing the lowest possible gain. This in turn is conducive to sensor noise disturbance rejection, avoidance of actuator saturation, and excitation of high frequency modes.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Multimission Aircraft Design Study
In the most recent years, the Command, Control and Communications, Counter Measures, Intelligence, Surveillance and Reconnaissance (C3CMISR) aircrafts are used commonly in many NATO and UN Operations around the world. These aircrafts are AWACS, JSTARS, Rivet Joint, Compass Call and ABCCC. They provide close air support in the name of airborne surveillance, ground moving target surveillance, target reconnaissance, jamming, and command, control and communications issues in operational environments. Those aircrafts are tasked with a wide variety of missions than ever before in operational theaters and each one of them comprises a specific amount of cost and risk factors. As a new vision, while replacing the existing legacy systems, multi-mission architectures are taken into consideration for the C3CMISR missions. The stated objective is designing a one tail number Multi-Mission Aircraft (MMA) that includes all the C3CMISR tasks on one airframe. This study seeks some comments and advises about the MMA design technical feasibility. In order to search for these comments, four notional operational scenarios are created. First of all existing C3CMISR aircrafts are considered and evaluated in these operational scenarios and then different MMA architectures are defined and compared with the legacy systems in the name of adequacy.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
The Canning of Foods
"The Canning of Foods," originally published in 1912, offers a detailed look into the methods employed in commercial canning during the early 20th century. Authored by A. W. Bitting, in conjunction with the United States Bureau of Chemistry and the Department of Agriculture, this volume provides valuable insights into the techniques and processes used to preserve food on a large scale. This historical text explores the various steps involved in canning, from preparation and processing to sealing and sterilization. It serves as a fascinating resource for those interested in the history of food technology and the evolution of the food industry. Whether you're a historian, a culinary enthusiast, or simply curious about the past, this book offers a unique glimpse into a bygone era of food preservation.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Isomer Energy Source for Space Propulsion Systems
Presented in this work are the results of an investigation of alternative means for powering spacecraft and launch vehicles with energy sources other than chemical combustion. Nuclear Thermal Propulsion (NTR) and the energy release of a nuclear spin isomer present potential for increased rocket performance with a compact, high-energy fuel sources replacing the combustion engines of the Delta IV-H 1st and 2nd stage vehicles. NTR was represented by the Nuclear Engine for Rocket Vehicle Application, CERMET, and the Particle Bed Reactor (PBR) fission designs, while the isomer hafnium-178-m2 was investigated in a PBR configuration. Energy storage levels of 1.3 GJ/g are possible with this material, though the successful triggering and maintenance of a chain reaction in this material are still debated topics within the scientific community. The best application for either technology is as an upper stage vehicle with the shielding requirements reduced to that of just a shadow shield between the core and the spacecrafts upper structure.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
A New Collection of Genuine Receipts, for the Preparation and Execution of Curious Arts, and Interesting Experiments ... To Which is Added, a Complete and Much Approved System of Dyeing, in All Its Va
Delve into the past with "A New Collection of Genuine Receipts," a fascinating compilation from 1831 offering insights into early 19th-century arts, sciences, and domestic practices. This intriguing book provides a wide array of 璽€~receipts' (recipes) for various curious arts and interesting experiments, reflecting the period's fascination with both practical skills and scientific inquiry. The collection covers diverse subjects from household tips and cleaning solutions to more elaborate experimental procedures. It also includes a comprehensive system of dyeing, detailing methods and techniques for achieving various colors and effects. This section would be invaluable for understanding historical textile practices. This volume offers a unique glimpse into the daily life, scientific interests, and technological capabilities of a bygone era. A valuable resource for historians, artisans, and anyone curious about the past, "A New Collection of Genuine Receipts" preserves a wealth of knowledge and provides a tangible link to the ingenuity of the early 19th century.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Tools for the Conceptual Design and Engineering Analysis of Micro Air Vehicles
Micro Air Vehicles (MAV) are a subset of Unmanned Aircraft (UAS) that are up to two orders of magnitude smaller than manned systems. Near-Earth environments, such as forests, caves, tunnels and urban structures make reconnaissance, surveillance and search-and-rescue missions difficult and dangerous to accomplish. Therefore, MAVs are considered ideal for these types of missions. However, the data using full size aircraft is inadequate to characterize miniature aircraft parameters due to the lower Reynolds numbers and low aspect ratio (LAR) wings and impact of wing-propeller interactions. The main objectives of this research were to: collect and synthesize the available data/tools; create a statistically integrated database/tool set of MAV designs for conceptual design trades; validate the tool set using published experimental data; synthesize and model a prototype design using conceptual and empirical analysis; highlight MAV-specific design criteria and identify gaps in existing data for later research.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Scramjet Fuel Injection Array Optimization Utilizing Mixed Variable Pattern Search With Kriging Surrogaates
Fuel-air mixing analysis of scramjet aircraft is often performed through experimental research or computational -uid dynamics (cfd) algorithms. Design optimization with these approaches is often impossible under a limited budget due to their high cost per run. This investigation uses jetpen, a known inexpensive analysis tool, to build upon a previous case study of scramjet design optimization. Mixed Variable Pattern Search (mvps) is compared to evolutionary algorithms in the optimization of two scramjet designs. The rst revisits the previously studied approach and compares the quality of mvps to prior results. The second applies mvps to a new scramjet design in support of the Hypersonic International Flight Research Experimentation (hifire). The results demonstrate the superiority of mvps over evolutionary algorithms and paves the way for design optimization with more expensive approaches.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Cubesat Packaged Electrospray Thruster Evaluation for Enhanced Operationally Responsive Space Capabilities
A new specialized electrospray thruster with a potential to be used with a 3-U CubeSat was operated. The key difference in this thruster from traditional colloid thrusters is the porous stainless steel surface used for the emission sites. With this porous surface the actual location and number of the Taylor cones formations vary with changing fuel flow. The understanding of these formations is discussed with low, moderate, and high flow rates. The limitations of the experiment and observed system response are discussed. Due to these limitations, the colloid thruster was only able to operate in the low mass flow rate regime.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Effects Of Boundary Layer Flow Control Using Plasma Actuator Discharges
This study addresses the usage and effects of atmospheric plasma discharges on the near wall flow conditions for a Pak-B low-pressure turbine blade. A plasma actuator was built normal to the freestream flow in a low-speed wind tunnel. The test section of the wind tunnel had a contoured upper wall geometry designed to mimic the suction side of a Pak-B turbine blade. A high frequency ac voltage source supplied three voltages in the kilovolt range at four Reynolds numbers in the experiment, between 10,000 and 103,000. The effect of the plasma on the near-wall boundary layer conditions was evaluated at each of the Reynolds numbers and each of the three voltage levels. Particle image velocimetry (PIV) was used to determine the 2D boundary layer characteristics of the flow. This research showed that the plasma discharges were able to dramatically increase the flow velocity near the wall; however, the plasma was unable to reattach an already detached boundary layer. Additionally, multiple manufacturing techniques were evaluated in an effort to make the electrodes more usable in turbine blade applications.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
A Technology Review of Smart Sensors With Wireless Networks for Applications in Hazardous Work Environments
Workers in hazardous environments such as mining are constantly exposed to the health and safety hazards of dynamic and unpredictable conditions. One approach to enable them to manage these hazards is to provide them with situational awareness: real-time data (environmental, physiological, and physical location data) obtained from wireless, wearable, smart sensor technologies deployed at the work area. The scope of this approach is limited to managing the hazards of the immediate work area for prevention purposes; it does not include technologies needed after a disaster. Three critical technologies emerge and converge to support this technical approach: smart-wearable sensors, wireless sensor networks, and low-power embedded computing. The major focus of this report is on smart sensors and wireless sensor networks. Wireless networks form the infrastructure to support the realization of situational awareness; therefore, there is a significant focus on wireless networks. Lastly, the "Future Research" section pulls together the three critical technologies by proposing applications that are relevant to mining. The applications are injured miner (person-down) detection; a wireless, wearable remote viewer; and an ultrawide band smart environment that enables localization and tracking of humans and resources. The smart environment could provide location data, physiological data, and communications (video, photos, graphical images, audio, and text messages).This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
PIV-Based Examination of Deep Stall on an Oscillating Airfoil
A number of studies suggest that the deep stall flow fields produced by a pure-pitch and a pure-plunge oscillating airfoil are equivalent, when effective angles of attack are matched. This assumption is examined using particle image velocimetry (PIV). Sinusoidal oscillations of a pure-plunge and pure-pitch airfoil with matched reduced frequency k = 3.93 and with kinematically equivalent amplitudes of effective angle of attack are comparatively examined using results of PIV in a free surface water tunnel at AFRL/RB, Wright Patterson AFB. Experiments were conducted at Re = 10,000 and Re = 40,000, based on free stream velocity and airfoil chord, in order to observe the legitimacy of assuming Reynolds number insensitivity on the respective flow fields. Comparisons are made to computational flow field results collected in a separate, but coordinated, CFD effort. Results for both the pure-plunge case and the pure-pitch case confirm the Reynolds number insensitivity for the high frequency motions researched here. The resulting flow fields for pure-plunge case and the pure-pitch case were vastly different. Experimental results for the pure-plunge case closely resembled those achieved by computation. However, the pure-pitch case experimental and computation results were dissimilar even after considering possible wall effects of the water tunnel. The flow field disagreement between the two motions is not surprising considering trailing edge kinematic dissimilarities.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Biomimetic Micro Air Vehicle Testing Development and Small Scale Flapping-Wing Analysis
The purpose of this research was to develop testing methods capable of analyzing the performance of a miniature flapping-winng mechanism that can later be adapted for the development a Biomimetric flapping-wing micro vehicle (MAV). Three small scale flapping mechanisms capable of single plane flapping, flapping with active pitch control, and flapping/pitch with out-of-plane movement were designed using SolidWorks. The flapping mechanism was mounted on a supported by air bearings, and thrust was measured for a variety of conditions. The testing was conducted using wings composed of fiber and Mylar in four different size configurations, with flapping speeds ranging from 3.5 - 15Hertz. The thrust was measured using anaxially mounted 50 gram load cell which resulted in an accuracy of + 0.1 gram. The flapping mechanism was then mounted on a 6-component force balance to measure dynamic loading, which demonstrated the ability to gather time-accurate data within a single flapping stroke at speeds as high as 15Hz. High speed cameras were also used for capturing images of how the structure of the wing changed at various testing conditions. Overall this research successfully demonstrated testing procedures that can be utilized in developing scale flapping-wing micro air vehicles.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
CFD Analysis of Experimental Wing and Winglet for FalconLAUNCH 8 and the ExFIT Program
Reusable launch vehicles have many benefits over their expendable counterparts. These benefits range from cost reductions to increased functionality of the vehicles. Further research is required in the development of the technology necessary for reusable launch vehicles to come to fruition. The Air Force Institute of Technology's future involvement in the ExFIT program will entail designing and testing of a new wing tip mounted vertical stabilizer in the hypersonic regime. One proposed venue for experimentation is to utilize the United States Air Force Academy's FalconLAUNCH Program which annually designs, builds, and launches a sounding rocket capable of reaching hypersonic speeds. In the Spring of 2010 an experimental wing geometry will be flown on FalconLAUNCH VIII for the ExFIT Program. The following study outlines the Computational Fluid Dynamics analysis used to determine lift and drag characteristics as well as temperature distributions of the wing geometry before testing to produce a successful launch. A majority of this analysis focused on the effects caused by shock waves forming on the winglet and their impact on the lifting characteristics and temperature distribution of the wing. Ultimately a recommendation of a 3o angle of attack is given for the experimental wings on the rocket. At this configuration the lift and drag generated by the experimental wings will be at a minimum allowing for greater stability and speed throughout the flight of the rocket.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Satellite-Based Fusion of Image/Inertial Sensors for Precise Geolocation
The ability to produce high-resolution images of the Earth's surface from space has flourished in recent years with the continuous development and improvement of satellite-based imaging sensors. Earth-imaging satellites often rely on complex onboard navigation systems, with dependence on Global Positioning System (GPS) tracking and/or continuous post-capture georegistration, to accurately geolocate ground targets of interest to either commercial and military customers. Consequently, these satellite systems are often massive, expensive, and susceptible to poor or unavailable target tracking capabilities in GPS-denied environments. Previous research has demonstrated that a tightlycoupled image-aided inertial navigation system (INS), using existing onboard imaging sensors, can provide significant target tracking improvement over that of conventional navigation and tracking systems. Satellite-based image-aided navigation is explored as a means of autonomously tracking stationary ground targets by implementing feature detection and recognition algorithms to accurately predict a ground target's pixel location within subsequent satellite images. The development of a robust satellite-based image-aided INS model offers a convenient, low-cost, low-weight and highly accurate solution to the geolocation precision problem, without the need of human interaction or GPS dependency, while simultaneously providing redundant and sustainable satellite navigation capabilities.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
An Approach to the Constrained Design of Natural Laminar Flow Airfoils
A design method has been developed by which an airfoil with a substantial amount of natural laminar flow can be designed, while maintaining other aerodynamic and geometric constraints. After obtaining the initial airfoil's pressure distribution at the design lift coefficient using an Euler solver coupled with an integml turbulent boundary layer method, the calculations from a laminar boundary layer solver are used by a stability analysis code to obtain estimates of the transition location (using N-Factors) for the starting airfoil. A new design method then calculates a target pressure distribution that will increase the larninar flow toward the desired amounl An airfoil design method is then iteratively used to design an airfoil that possesses that target pressure distribution. The new airfoil's boundary layer stability characteristics are determined, and this iterative process continues until an airfoil is designed that meets the laminar flow requirement and as many of the other constraints as possible.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Distributed Parallel Processing and Dynamic Load Balancing Techniques for Multidisciplinary High Speed Aircraft Design
Multidisciplinary design optimization (MDO) for large-scale engineering problems poses many challenges (e.g., the design of an efficient concurrent paradigm for global optimization based on disciplinary analyses, expensive computations over vast data sets, etc.) This work focuses on the application of distributed schemes for massively parallel architectures to MDO problems, as a tool for reducing computation time and solving larger problems. The specific problem considered here is configuration optimization of a high speed civil transport (HSCT), and the efficient parallelization of the embedded paradigm for reasonable design space identification. Two distributed dynamic load balancing techniques (random polling and global round robin with message combining) and two necessary termination detection schemes (global task count and token passing) were implemented and evaluated in terms of effectiveness and scalability to large problem sizes and a thousand processors. The effect of certain parameters on execution time was also inspected. Empirical results demonstrated stable performance and effectiveness for all schemes, and the parametric study showed that the selected algorithmic parameters have a negligible effect on performance.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Rotorcraft Flight Control Design Using Quantitative Feedback Theory and Dynamic Crossfeeds
A multi-input, multi-output controls design with robust crossfeeds is presented for a rotorcraft in near-hovering flight using quantitative feedback theory (QFT). Decoupling criteria are developed for dynamic crossfeed design and implementation. Frequency dependent performance metrics focusing on piloted flight are developed and tested on 23 flight configurations. The metrics show that the resulting design is superior to alternative control system designs using conventional fixed-gain crossfeeds and to feedback-only designs which rely on high gains to suppress undesired off-axis responses. The use of dynamic, robust crossfeeds prior to the QFT design reduces the magnitude of required feedback gain and results in performance that meets current handling qualities specifications relative to the decoupling of off-axis responses. The combined effect of the QFT feedback design following the implementation of low-order, dynamic crossfeed compensator successfully decouples ten of twelve off-axis channels. For the other two channels it was not possible to find a single, low-order crossfeed that was effective.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Crack Turning in Integrally Stiffened Aircraft Structures
Current emphasis in the aircraft industry toward reducing manufacturing cost has created a renewed interest in integrally stiffened structures. Crack turning has been identified as an approach to improve the damage tolerance and fail-safety of this class of structures. A desired behavior is for skin cracks to turn before reaching a stiffener, instead of growing straight through. A crack in a pressurized fuselage encounters high T-stress as it nears the stiffener--a condition favorable to crack turning. Also, the tear resistance of aluminum alloys typically varies with crack orientation, a form of anisotropy that can influence the crack path. The present work addresses these issues with a study of crack turning in two-dimensions, including the effects of both T-stress and fracture anisotropy. Both effects are shown to have relation to the process zone size, an interaction that is central to this study. Following an introduction to the problem, the T-stress effect is studied for a slightly curved semi-infinite crack with a cohesive process zone, yielding a closed form expression for the future crack path in an infinite medium. For a given initial crack tip curvature and tensile T-stress, the crack path instability is found to increase with process zone size. Fracture orthotropy is treated using a simple function to interpolate between the two principal fracture resistance values in two-dimensions. An extension to three-dimensions interpolates between the six principal values of fracture resistance. Also discussed is the transition between mode I and mode II fracture in metals. For isotropic materials, there is evidence that the crack seeks out a direction of either local symmetry (pure mode I) or local asymmetry (pure mode II) growth. For orthotropic materials the favored states are not pure modal, and have mode mixity that is a function of crack orientation.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
An Experimental Study of the Effects of Automation on Pilot Situational Awareness in the Datalink ATC Environment
An experiment to study how automation, when used in conjunction with datalink for the delivery of air traffic control (ATC) clearance amendments, affects the situational awareness of aircrews was conducted. The study was focused on the relationship of situational awareness to automated Flight Management System (FMS) programming and the readback of ATC clearances. Situational awareness was tested by issuing nominally unacceptable ATC clearances and measuring whether the error was detected by the subject pilots. The experiment also varied the mode of clearance delivery: Verbal, Textual, and Graphical. The error detection performance and pilot preference results indicate that the automated programming of the FMS may be superior to manual programming. It is believed that automated FMS programming may relieve some of the cognitive load, allowing pilots to concentrate on the strategic implications of a clearance amendment. Also, readback appears to have value, but the small sample size precludes a definite conclusion. Furthermore, because textual and graphical modes of delivery offer different but complementary advantages for cognitive processing, a combination of these modes of delivery may be advantageous in a datalink presentation.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Design Concepts for Zero-G Whole Body Cleansing on ISS Alpha
This document was originally published in 1997 as a International Space University Master of Space Studies student's project. While the specifics may be a little dated, the results gleaned are still relevant and valid. Johnson Space Center is now abuzz with preparations for the International Space Station. The work on the various systems for the U.S. Habitation Module will begin in 1998. As a prelude, the Flight Crew Support Division perceived the need to take a closer, more critical took at planning the Whole Body Cleansing function for ISS. This report is an endeavour to retrieve all data available on whole body cleansing mechanisms used, past and present, by the Russians and the Americans, analyze it and create design concepts for products/product systems for zero-g whole body cleansing on ISS Alpha, for typical duration of about 90 days. This report takes a close look at the Skylab collapsible shower, the Mir shower/sauna, the full body cleansing methods currently in use onboard the Space Shuttle and Mir and at the Whole Body Shower designed and tested for Space Station Freedom. It attempts to "listen" carefully to what the Mir astronauts (Norm Thagard, Shannon Lucid and John Blaha) have to say about their personal hygiene experiences during their recent stays on Mir. The findings in the report call for a change in paradigm. What is good for Earth conditions is not necessarily good for Zero-g! It concludes that a shower is not a good idea for the ISS. The final concept that is proposed reflects very strongly what the Mir astronauts would like to have and to use onboard a station like the ISS, The report concludes with directions of how to take the "idea" further and realize it in the form of a product system for Whole Body Cleansing onboard the ISS.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Development of Autonomous Unmanned Aerial Vehicle Research Platform
The Advanced Navigation Technology (ANT) Center at the Air Force Institute of Technology (AFIT) conducts extensive research in advanced guidance, navigation, and control to exploit the full potential of autonomous Unmanned Aerial Vehicles (UAV). The research in this thesis describes a UAV research platform developed to support the ANT Center's goals. This platform is now the bedrock for UAV simulation and local flight test at AFIT. The research has three major components. The first component includes development of a physical, inertial, and aerodynamic model representing an existing aircraft. A systematic analysis of the airframe leads to a complete geometric, inertial, and aerodynamic representation. The airframe analysis includes the use of USAF Digital Datcom, an aerodynamic modeling software tool. Second is the development and implementation of a non-linear, six degree of freedom simulation, employing the developed model. Constructed in Matlab/SIMULINK, the simulation enables control design and pre-flight analysis throughout the entire flight envelope. Detailed post-flight analysis is also performed in Matlab/SIMULINK. Additionally, a Hardware in the Loop benchmark simulation is constructed for initial flight test planning as well as test team training.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Micro-Mechanical Voltage Tunable Fabry-Perot Filters Formed in (111) Silicon
The MEMS (Micro-Electro-Mechanical-Systems) technology is quickly evolving as a viable means to combine micro-mechanical and micro-optical elements on the same chip. One MEMS technology that has recently gained attention by the research community is the micro-mechanical Fabry-Perot optical filter. A MEMS based Fabry-Perot consists of a vertically integrated structure composed of two mirrors separated by an air gap. Wavelength tuning is achieved by applying a bias between the two mirrors resulting in an attractive electrostatic force which pulls the mirrors closer. In this work, we present a new micro-mechanical Fabry-Perot structure which is simple to fabricate and is integratable with low cost silicon photodetectors and transistors. The structure consists of a movable gold coated oxide cantilever for the top mirror and a stationary Au/Ni plated silicon bottom mirror. The fabrication process is single mask level, self aligned, and requires only one grown or deposited layer. Undercutting of the oxide cantilever is carried out by a combination of RIE and anisotropic KOH etching of the (111) silicon substrate. Metallization of the mirrors is provided by thermal evaporation and electroplating. The optical and electrical characteristics of the fabricated devices were studied and show promissing results. A wavelength shift of 120nm with 53V applied bias was demonstrated by one device geometry using 6.27 micrometer air gap. The finesse of the structure was 2.4. Modulation bandwidths ranging from 91KHz to greater than 920KHz were also observed. Theoretical calculations show that if mirror reflectivity, smoothness, and parallelism are improved, a finesse of 30 is attainable. The predictions also suggest that a reduction of the air gap to 1 micrometer results in an increased wavelength tuning range of 175 nm with a CMOS compatible 4.75V.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
EPA Example Construction SWPPP
The U.S. Environmental Protection Agency (EPA) was introduced on December 2, 1970 by President Richard Nixon. The agency is charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress. The EPA's struggle to protect health and the environment is seen through each of its official publications. These publications outline new policies, detail problems with enforcing laws, document the need for new legislation, and describe new tactics to use to solve these issues. This collection of publications ranges from historic documents to reports released in the new millennium, and features works like: Bicycle for a Better Environment, Health Effects of Increasing Sulfur Oxides Emissions Draft, and Women and Environmental Health.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Handbook of Constructed Wetlands
The U.S. Environmental Protection Agency (EPA) was introduced on December 2, 1970 by President Richard Nixon. The agency is charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress. The EPA's struggle to protect health and the environment is seen through each of its official publications. These publications outline new policies, detail problems with enforcing laws, document the need for new legislation, and describe new tactics to use to solve these issues. This collection of publications ranges from historic documents to reports released in the new millennium, and features works like: Bicycle for a Better Environment, Health Effects of Increasing Sulfur Oxides Emissions Draft, and Women and Environmental Health.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Development of a Simulation Capability for the Space Station Active Rack Isolation System
To realize quality microgravity science on the International Space Station, many microgravity facilities will utilize the Active Rack Isolation System (ARIS). Simulation capabilities for ARIS will be needed to predict the microgravity environment. This paper discusses the development of a simulation model for use in predicting the performance of the ARIS in attenuating disturbances with frequency content between 0.01 Hz and 10 Hz. The derivation of the model utilizes an energy-based approach. The complete simulation includes the dynamic model of the ISPR integrated with the model for the ARIS controller so that the entire closed-loop system is simulated. Preliminary performance predictions are made for the ARIS in attenuating both off-board disturbances as well as disturbances from hardware mounted onboard the microgravity facility. These predictions suggest that the ARIS does eliminate resonant behavior detrimental to microgravity experimentation. A limited comparison is made between the simulation predictions of ARIS attenuation of off-board disturbances and results from the ARIS flight test. These comparisons show promise, but further tuning of the simulation is needed.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Capillary Flow in an Interior Corner
The design of fluids management processes in the low-gravity environment of space requires an accurate model and description of capillarity-controlled flow in containers of irregular geometry. Here we consider the capillary rise of a fluid along an interior corner of a container following a rapid reduction in gravity. The analytical portion of the work presents an asymptotic formulation in the limit of a slender fluid column, slight surface curvature along the corner, small inertia, and low gravity. New similarity solutions are found and a list of closed form expressions is provided for flow rate and column length. In particular, it is found that the flow is proportional to t(exp 1/2) for a constant height boundary condition, t(exp 2/5) for a spreading drop, and t(exp 3/5) for constant flow. In the experimental portion of the work, measurements from a 2.2s drop tower are reported. An extensive data set, collected over a previously unexplored range of flow parameters, includes estimates of repeatability and accuracy, the role of inertia and column slenderness, and the effects of corner angle, container geometry, and fluid properties. Comprehensive comparisons are made which illustrate the applicability of the analytic results to low-g fluid systems design.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
The Balloon. Noteworthy Aerial Voyages, From the Discovery of the Balloon to the Present Time
"The Balloon: Noteworthy Aerial Voyages, From the Discovery of the Balloon to the Present Time" offers a fascinating glimpse into the early history of ballooning. Published in 1879, this volume chronicles significant aerial voyages and developments in balloon technology from its inception. Authored by the American Aeronautic Society of New York, it provides detailed accounts of pioneering flights, technical innovations, and the social impact of early aviation. Readers will discover the excitement and challenges faced by early aeronauts as they navigated the skies in these novel contraptions. This book serves as a valuable historical resource for anyone interested in the evolution of aviation and the daring individuals who pushed the boundaries of what was possible.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Looking Squarely at the Water Power Problem ..
"Looking Squarely at the Water Power Problem" examines the legal and practical aspects of water power development in the early 20th century. Authored by Henry Joshua Pierce, with reference to United States laws from 1914, this work delves into the challenges and opportunities surrounding the utilization of water resources for power generation. It offers insights into the regulatory environment and engineering considerations of the time, making it a valuable resource for understanding the historical context of hydroelectric power and water management. The book provides a snapshot of the early debates and legislative efforts related to harnessing water power, relevant to legal scholars, historians of technology, and anyone interested in the evolution of energy policy.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
A Collection of Valuable Formulas and Recipes for the Manufacturer, Merchant, Farmer and Household
"A Collection of Valuable Formulas and Recipes for the Manufacturer, Merchant, Farmer and Household" offers a fascinating glimpse into early 20th-century life and industry. Compiled in 1915, this book is a treasure trove of practical knowledge, presenting a wide array of formulas and recipes intended to aid manufacturers, merchants, farmers, and everyday households. From crafting essential goods to tackling common household challenges, the book provides detailed instructions and ingredients for a variety of applications. This collection is not only a valuable resource for those interested in historical practices but also a testament to the ingenuity and resourcefulness of a bygone era. Discover the time-tested methods that sustained communities and industries in this remarkable compilation.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Surface Acoustic Wave Devices as Chemical Vapor Sensors
The objective of this research is to develop a transducer for recognition of molecular changes in the presence of chemical vapors. This transducer is tested using polymer sensing layers known to be sensitive to ethanol vapors. A surface acoustic wave device is selected as the transducer element due to low cost, high surface sensitivity, and sensitivity. These devices are designed and fabricated in-house, and a polymer sensing layer applied. The frequency response of the coated device is probed both with and without the presence of airborne ethanol molecules in a vapor stream. By analyzing the changes in the amplitude and phase of the frequency response near resonance, vapor detection was conclusively demonstrated. Additionally, the mechanism of change was identified, allowing future work in optimizing the sensitivity of the device. Other future work will include application of a biomolecular sensing layer, design of circuitry for a portable devices, and fabrication of a MEMS preconcentrator. The final goal of the project is a portable sensor array using surface acoustic wave devices coated with different bio-molecules.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
