Dynamic Wireless Power Transfer System For The Unmanned Aerial Vehicles,
2014
Purdue University
Dynamic Wireless Power Transfer System For The Unmanned Aerial Vehicles, Tae Sup Lee
Open Access Theses
UAVs have limitless applications to help our daily lives for the autonomous operations. UAVs have a limited power capacity due to weight constraints and are therefore not able to travel long distances. Ground stations for recharging UAVs throughout different points can increase the flight time of the UAVs with the current UAV battery capacity. This study investigates how the wireless charging system for the ground station can be made more robust when there are misalignments. The wireless charging system is monitored by an Arduino, micro controller, to assess the current condition of charging. The Arduino is able to change the …
Mode I Fatigue Delamination Onset Of Carbon Fibre Reinforced Polymer With Novel Post-Cure Throughthickness Reinforcement,
2014
Purdue University
Mode I Fatigue Delamination Onset Of Carbon Fibre Reinforced Polymer With Novel Post-Cure Throughthickness Reinforcement, Christopher John Kourloufas
Open Access Theses
A novel trough thickness reinforcement (TTR) technique, proposed by Kravchenko et al., has been tested under mode I fatigue loading conditions in order to investigate characterisation of the onset of delamination growth in unidirectional 8552/IM7. The experimental results, following standard test method ASTM D6115-13, indicate that the mode I fatigue delamination onset behaviour can be altered by the inclusion of TTR both ahead and behind the crack tip. Tests have been conducted at a wide range of maximum displacement values, corresponding to percentages of the critical fracture toughness value determined for the maternal, GIC . The results were found …
Evaluating Intensity As A Controller Function For Nextgen Scenarios With Increased Capacity,
2014
Purdue University
Evaluating Intensity As A Controller Function For Nextgen Scenarios With Increased Capacity, Caitlin Anne Surakitbanharn
Open Access Theses
Automated separation assurance is the most mature concept to handle increasing airspace traffic and capacity needs, yet the system lacks a way to pre-emptively identify aircraft separation problems. The intensity control measure looks to find situations where if an aircraft pair makes an unplanned change in heading or altitude at the wrong moment, an unrecoverable situation arises. This research analyzes static, open loop air traffic data in an en-route sector to determine how many high intensity aircraft pairs (HIP) exist per minute, and if the intensity measure is a safely manageable function for air traffic controllers. It is found that …
Coupled Fluid-Thermal Analysis Of Low-Pressure Sublimation And Condensation With Application To Freeze-Drying,
2014
Purdue University
Coupled Fluid-Thermal Analysis Of Low-Pressure Sublimation And Condensation With Application To Freeze-Drying, Arnab Ganguly
Open Access Dissertations
Freeze-drying is a low-pressure, low-temperature condensation pumping process widely used in the manufacture of bio-pharmaceuticals for removal of solvents by sublimation. The goal of the process is to provide a stable dosage form by removing the solvent in such a way that the sensitive molecular structure of the active substance is least disturbed. The vacuum environment presents unique challenges for understanding and controlling heat and mass transfer in the process. As a result, the design of equipment and associated processes has been largely empirical, slow and inefficient.^ A comprehensive simulation framework to predict both, process and equipment performance is critical …
Analysis Of The Interaction Of Two Parallel Surface Cracks,
2014
Purdue University
Analysis Of The Interaction Of Two Parallel Surface Cracks, Jeeyeon Hahn
Open Access Dissertations
The objective of this research is to analyze and predict the interaction of surface cracks that occur in parallel planes. Multiple cracks may form in aging aircraft that forms at stress concentrations such as fastener holes and notched components by stress corrosion and fatigue cracking. The lifetime of the structures are significantly affected by the interaction between these cracks. Depending on relative positions and orientations of neighboring cracks, local stress fields and crack driving forces can be affected by the presence of adjacent cracks. Even small subcritical cracks may rapidly grow to a size that will cause failure in service …
Trajectory Design In The Spatial Circular Restricted Three-Body Problem Exploiting Higher-Dimensional Poincare Maps,
2014
Purdue University
Trajectory Design In The Spatial Circular Restricted Three-Body Problem Exploiting Higher-Dimensional Poincare Maps, Amanda F. Haapala
Open Access Dissertations
In this investigation, the role of higher-dimensional Poincaré maps in facilitating trajectory design is explored for a variety of applications. To begin, existing strategies to implement Poincaré maps for trajectory design applications in the spatial CR3BP are evaluated. New applications for these strategies are explored, including an analysis of the natural motion of Jupiter-family comets that experience temporary capture about Jupiter, and the search for periodic orbits in the vicinity of the primary bodies in the spatial problem. Because current strategies to represent higher-dimensional maps, generally, lead to a loss of information, new approaches to represent all information contained in …
Measurement Of Combustion Response To Transverse Modes At High Pressure,
2014
Purdue University
Measurement Of Combustion Response To Transverse Modes At High Pressure, Matthew Kenneth Wierman
Open Access Dissertations
A two dimensional transverse combustor capable of producing and modulating an unstable flowfield was tested at Purdue. The combustor used an array of coaxial ox-centered shear injector elements. The oxidizer posts were able to be discretely changed in length between tests to investigate different post resonance conditions. A single Study element was placed in the middle of the driven unsteady flowfield so its response could be measured using pressure measurement and high speed imagery. This approach was supported by past testing of the longitudinal Continuously Variable Resonance Combustor and past transverse chambers. Mean flow rates and pressures were fixed across …
Crossflow Instability And Transition On A Circular Cone At Angle Of Attack In A Mach-6 Quiet Tunnel,
2014
Purdue University
Crossflow Instability And Transition On A Circular Cone At Angle Of Attack In A Mach-6 Quiet Tunnel, Christopher A. C Ward
Open Access Dissertations
To investigate the effect of roughness on the stationary crossflow vortices, roughness elements 2 inches from the nosetip were created in a Torlon insert section of a 7-deg half-angle cone at 6-deg angle of attack in the Boeing/AFOSR Mach-6 Quiet Tunnel. Roughness elements with depths and diameters on the order of 500 microns were found to have a significant effect on the generation of the stationary vortices and the location of crossflow-induced transition under quiet flow. Crossflow-induced transition was measured under fully quiet flow. The controlled roughness elements also appeared to dominate the generation of the vortices, overwhelming the effect …
Applications Of Femtosecond Coherent Anti-Stokes Raman Scattering In Combustion,
2014
Purdue University
Applications Of Femtosecond Coherent Anti-Stokes Raman Scattering In Combustion, Claresta Nicole Dennis
Open Access Dissertations
The dissertation deals with the further development of chirped-probe-pulse femtosecond coherent anti-Stokes Raman spectroscopy (CPP fs-CARS) for applications of gas phase thermometry and extension to methane concentration measurements. The main effort has been to assess the usefulness and robustness of the technique in turbulent combustors of practical interest. A primary aim has been to evaluate the use of CPP fs-CARS for vibrational N2 thermometry in a highly turbulent environment. It has been suggested that due to the laser beam temporal overlap required for fs-CARS signal generation, the technique would be unsuccessful due to beam propagation retardation effects from density …
Investigation Of Condensed And Early Stage Gas Phase Hypergolic Reactions,
2014
Purdue University
Investigation Of Condensed And Early Stage Gas Phase Hypergolic Reactions, Jacob Daniel Dennis
Open Access Dissertations
Traditional hypergolic propellant combinations, such as those used on the space shuttle orbital maneuvering system first flown in 1981, feature hydrazine based fuels and nitrogen tetroxide (NTO) based oxidizers. Despite the long history of hypergolic propellant implementation, the processes that govern hypergolic ignition are not well understood. In order to achieve ignition, condensed phase fuel and oxidizer must undergo simultaneous physical mixing and chemical reaction. This process generates heat, intermediate condensed phase species, and gas phase species, which then may continue to react and generate more heat until ignition is achieved. The process is not well understood because condensed and …
Investigation Of Pulse Detonation Engine Flow Conditions For Turbomachinery Integration,
2014
Embry-Riddle Aeronautical University
Investigation Of Pulse Detonation Engine Flow Conditions For Turbomachinery Integration, Luis Estefano Ferrer-Vidal EspañA-Heredia
Doctoral Dissertations and Master's Theses
Pressure gain combustion has been known to be more thermodynamically efficient than its constant pressure counterpart, which employs deflagration. Integration of pressure gain combustors into gas turbine engines has been and still is one of the most important challenges facing the gas turbine industry. Pressure gain combustion devices are inherently unsteady. This unsteadiness affects turbomachinery components designed using steady operation assumptions, and results in mechanical inefficiencies which could outweigh the thermal efficiency benefits. Understanding of turbine components specifically made to operate in the exhaust conditions provided by a pressure gain combustor may yield new turbine design paradigms. As a first …
Reduction Of Secondary Flow Losses In A Turbine For Use In Man-Portable Power Generation,
2014
Embry-Riddle Aeronautical University - Daytona Beach
Reduction Of Secondary Flow Losses In A Turbine For Use In Man-Portable Power Generation, Andrew J. Yatsko
Doctoral Dissertations and Master's Theses
As the world has moved into a more energy-demanding environment, there has been the push for higher energy density in a smaller package. One of the potential solutions is through the application of a gas turbine engine; yet the challenge is extracting the energy efficiently through the small components. The focus of the research is on the turbine components and how the secondary flow losses from the generated airfoil shapes can be reduced to improve component performance. One of the secondary flow loss items to be addressed is the generation of the Horseshoe Vortex. The Horseshoe Vortex is an aerodynamic …
The Effects Of Rewards On The Ability Of An Autonomous Uav Controlled By A Reinforcement Learning Agent To Accomplish A Target Localization Task,
2014
Embry-Riddle Aeronautical University
The Effects Of Rewards On The Ability Of An Autonomous Uav Controlled By A Reinforcement Learning Agent To Accomplish A Target Localization Task, Hemali Dinesh Virani
Doctoral Dissertations and Master's Theses
The need for Unmanned Aerial System (UASs) is increasing in the fields of science, security, military and others. With an increasing number of challenges faced by mankind the need for system with advance autonomous and intelligent capabilities is growing rapidly. The required intelligent behavior can be achieved in an unmanned system with machine learning methods such as Reinforcement Learning (RL) theory. This theory presents algorithms which have the capability to learn how to adapt to its environment. Using RL methods, autonomous systems have the ability to use past experiences to improve future mission performance. In this research, the effects of …
Methods For Initial Relative Orbit Determination Using Angles-Only Observations,
2014
Old Dominion University
Methods For Initial Relative Orbit Determination Using Angles-Only Observations, Ethan M. Pratt
Mechanical & Aerospace Engineering Theses & Dissertations
An approximate second order nonlinear closed-form solution for three-dimensional relative motion assuming Keplerian dynamics and a circular reference track are applied to the relative initial orbit determination problem. A series of azimuth-elevation angular measurements locating a deputy satellite with respect to a chief satellite are coupled through the observation geometry with the nonlinear dynamics model for the relative motion in terms of linear, quadratic, and bilinear combinations of the deputy initial conditions and chief orbital elements. The resulting set of nonlinear measurement equations are analyzed, formulated, and solved using three separate non-iterative methods. By using a nonlinear dynamics model with …
Design Improvements For A Reusable Horizontal Takeoff And Landing Aircraft For Use On Mars,
2014
Old Dominion University
Design Improvements For A Reusable Horizontal Takeoff And Landing Aircraft For Use On Mars, Brian A. Skoog
Mechanical & Aerospace Engineering Theses & Dissertations
Unmanned aerial vehicle capabilities are required for expanded exploration of the Martian surface. These vehicles can not only gather data at an altitude otherwise unreachable by rovers and satellites, but also deliver small payloads and retrieve samples from distant off-site locations. Previous multi-purpose reusable Mars aircraft studies have been unable to achieve the flight ranges required for expanded exploration. This study has focused on increasing the range of prototype aircraft designs. Assuming that large precision cargo delivery capabilities have been developed and much of the infrastructure associated with a fixed Mars base is in place, the challenge of linking dispersed …
Laminar Deflagrated Flame Interaction With A Fluidic Jet Flow For Deflagration-To-Detonation Flame Acceleration,
2014
Old Dominion University
Laminar Deflagrated Flame Interaction With A Fluidic Jet Flow For Deflagration-To-Detonation Flame Acceleration, Joseph P. Mcgarry
Mechanical & Aerospace Engineering Theses & Dissertations
The concept of the Pulse Detonation Engine (PDE) has been of interest for centuries. The issue was originally studied to understand flame propagation in mine shafts after explosions due to methane buildup. The flames would travel down the shafts, transitioning to turbulent flames due to the roughness of the shaft walls, and accelerate to detonation, delivering powerful, destructive forces. The potential for efficient energy production was noticed, and the theory behind flame propagation was later applied to developing propulsion systems. Recently, researchers have begun to understand the full potential of PDEs to efficiently produce an immense amount of thrust due …
Design Of A Frequency-Selective Surface Strain Sensor,
2014
Missouri University of Science and Technology
Design Of A Frequency-Selective Surface Strain Sensor, Edward C. Kinzel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Frequency Selective Surfaces (FSS) have long been used in the RF/microwave community to control radar cross-section. The scattering parameters of the FSS form a signature which is a function of the frequency, element size and spacing, as well as the local electromagnetic environment. This paper considers a FSS as a strain sensor on the surface of a structural element. By interrogating the FSS with a series of polarized far-field measurements in a bistatic configuration the biaxial plane strain, including shear, can be resolved.
Experimental Uncertainty Associated With Traveling Wave Excitation,
2014
Air Force Institute of Technology
Experimental Uncertainty Associated With Traveling Wave Excitation, Geofrey S. Cox
Theses and Dissertations
This dissertation research produces the experimental techniques required to evaluate mistuning in any rotor. Within operation, a rotor is subjected to a unique pattern of frequencies acting to excite the rotor. Utilizing traveling wave excitation, a rotor's critical frequencies and the respective excitation pattern are reproduced. Individual rotor blade frequency response functions are evaluated and statistically analyzed. The experimental results serve to not only verify the degree to which a rotor is mistuned, but also to provide an indication of the forced response amplification the mistuning induces. Within the experiment, definitive specifications were developed to ensure peak rotor responses. Numerical …
A Comparison Of Afghanistan, Yuma, Az, And Manufactured Sands Melted On Eb-Pvd Thermal Barrier Coatings,
2014
Air Force Institute of Technology
A Comparison Of Afghanistan, Yuma, Az, And Manufactured Sands Melted On Eb-Pvd Thermal Barrier Coatings, Nathaniel P. Opie
Theses and Dissertations
Sand ingestion into military aircraft turbine engines from desert environments have tested the performance and life of the engine. In particular, turbine section blades and nozzles are coated with a molten glass when the sand is heated to melting temperatures. This molten glass attacks protective coatings on the surface of these parts. Further research is needed to understand the sands behavior on thermal barrier coatings (TBC) when heated to melting temperatures. Also, further research is needed with manufactured sand used in current engine testing to understand the sand ingestion discrepancies between test engines and operational engines. In this study natural …
Optimal Control Of Fully Routed Air Traffic In The Presence Of Uncertainty And Kinodynamic Constraints,
2014
Air Force Institute of Technology
Optimal Control Of Fully Routed Air Traffic In The Presence Of Uncertainty And Kinodynamic Constraints, Christopher D. Arendt
Theses and Dissertations
A method is presented to extend current graph-based Air Traffic Management optimization frameworks. In general, Air Traffic Management is the process of guiding a finite set of aircraft, each along its pre-determined path within some local airspace, subject to various physical, policy, procedural and operational restrictions. This research addresses several limitations of current graph-based Air Traffic Management optimization methods by incorporating techniques to account for stochastic effects, physical inertia and variable arrival sequencing. In addition, this research provides insight into the performance of multiple methods for approximating non-differentiable air traffic constraints, and incorporates these methods into a generalized weighted-sum representation …
