Aerospace Engineering Commons^™

Wireless Power Transfer In Autonomous Mobile Microgrids, Carl Greene

Dissertations, Master's Theses and Master's Reports

The ability to autonomously dock unmanned ground vehicles plays a key role in mobile micro-grids, where efficient power transfer is paramount. The approach utilized in this work allows for near-field wireless power transfer in remote locations with minimal support. Establishing a micro-grid power system connection autonomously using wireless power eliminates the arduous task of designing a complex, multiple degrees of freedom (MDOF) robotic arm. The work presented in this thesis focuses on both the hardware and software within the micro-grid system. This particular near-field wireless system consists of a primary and secondary set of modules, comprised of Litz wire coils, …

Performance Degradation Based On Importance Change And Application In Dissimilar Redundancy Actuation System, Yadong Zhang, Chao Zhang, Shaoping Wang, Rentong Chen, Mileta M. Tomovic

Engineering Technology Faculty Publications

The importance measure is a crucial method to identify and evaluate the system weak link. It is widely used in the optimization design and maintenance decision of aviation, aerospace, nuclear energy and other systems. The dissimilar redundancy actuation system (DRAS) is a key aircraft control subsystem which performs aircraft attitude and flight trajectory control. Its performance and reliability directly affect the aircraft flight quality and flight safety. This paper considers the influence of the Birnbaum importance measure (BIM) and integrated importance measure (IIM) on the reliability changes of key components in DRAS. The differences of physical fault characteristics of different …

Satellite Drag Coefficient Modeling For Thermosphere Science And Mission Operations, Piyush M. Mehta, Smriti N. Paul, Nicholas H. Crisp, Philip L. Sheridan, Christian Siemes, Günther March, Sean Bruinsma

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Satellite drag modeling remains the largest source of uncertainty affecting space operations in low Earth orbit. The uncertainty stems from inaccurate models for mass density and drag coefficient. Drag coefficient modeling also impacts scientific knowledge on the physics and dynamics of the upper atmosphere through the estimation of high-fidelity mass density from measurements of acceleration on-board satellites. Efforts over the last decade have pushed drag coefficient modeling in the right direction, however, have resulted in multiple methods and tools. We provide a comprehensive review of the drag coefficient modeling methods and tools. Current scale differences between thermospheric data sets mostly …

Effects Of Wheel Rotation On Long-Period Wake Dynamics Of The Drivaer Fastback Model, Matthew Aultman, Rodrigo Auza-Gutierrez, Kevin Disotell, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lattice Boltzmann method (LBM) simulations were performed to capture the long-period dynamics within the wake of a realistic DrivAer fastback model with stationary and rotating wheels. The simulations showed that the wake developed as a low-pressure torus regardless of whether the wheels were rotating. This torus shrank in size on the base in the case of rotating wheels, leading to a reduction in the low-pressure footprint on the base, and consequently a 7% decrease in the total vehicle drag in comparison to the stationary wheels case. Furthermore, the lateral vortex shedding experienced a long-period switching associated with the bi-stability in …

The Effects Of Geometry And Architecture Of Polymer Matrix Composites On Acoustic Emissions, John J. Bush, Alex D. Swartzentruber, Lukas B. Thompson, Sarah R. Pratt, Chris J. Kuhn

Williams Honors College, Honors Research Projects

The purpose of this project is to study how the variance of the geometry and architecture of polymer matrix composites (PMCs) affect the acoustic emissions measured whilst said structures are subjected to tensile stress. In these tests, a method called Modal AE will be utilized. In Modal AE, some relationships between sources and waves in various materials and geometries are presented in other papers/research. This study will focus on how different thickness and different makeup/ply patterns affect the acoustic emission tests. Some research has been completed and shown how energy attenuation affects the frequency content on PMCs similar to the …

Liquid Engine External Pressurizer (Leep), Emily Armbrust

Williams Honors College, Honors Research Projects

The purpose of this project is to take the current liquid rocket engine test stand design and implement an external pressurant instead of utilizing the 2-phase oxidizer vapor to pressurize itself and the fuel. The purpose behind the design is because the team is limited with the current design concerning burn time due to the amount of propellant they can put in the tanks and the pressure it can reach. The initial pressure is currently not held since there is no external input of mass into the tanks, as the propellant is leaving. Adding an external pressurant allow for the …

Fuel System To Envelope Interface, James Campbell

Williams Honors College, Honors Research Projects

*NOTE THIS PROJECT IS CONFIDENTIAL*

In this project, I will investigate solutions to interfacing a fuel system with a fabric skin section

Large, Complex Housing, Alyssa Carnicella

Williams Honors College, Honors Research Projects

The purpose of this capstone project was to develop a design for a High Voltage Direct Current (HVDC) generator housing with built-in passageways for oil to flow through and cool the machine. The machine should be made using advanced manufacturing. A 3D model concept was designed with the use of SolidWorks. The appropriate hand calculations were completed to ensure that the generator housing would contain the components within itself under various environmental conditions.. The model was then 3D printed to produce a prototype that displays the design features within the housing. The next stage of the project will include completing …

Digital Image Correlation System Design, Verification And Analysis, Tyler Kraft, Matthew J. Riczo, Andrew Chong

Williams Honors College, Honors Research Projects

Two dimensional digital image correlation provides an accurate and effective way to capture strain data on test sections with unusual or oblique geometries. The system requires a camera to record video footage, alignment fixtures and software to convert the footage into strain values. The system works by capturing the video footage of a specific portion of the specimen and comparing the movement of selected pixels. This is all done in the software GOM Correlate and Tracker. This test document outlines the setup, procedure, and validation steps to fulfill this goal. The setup involves a camera, tripod, blue lighting, and laser …

Autonomous Payload Design With Systems Engineering, Michael Downs, Christopher James Liebhart 2nd

Williams Honors College, Honors Research Projects

The design will be an autonomous payload consisting of auto deployment of a drone running an autonomous mission of mapping the terrain around a grounded rocket. The project is part of the Akronauts payload project for the 2022 Spaceport competition. It will include the development of a ground station for monitoring and controlling the drone and the transfer of live data to the station and a computer on board the rocket. The project will aim to use system engineering techniques to accomplish this in the hope of providing documentation and thus insight into the best way to develop a multi-disciplinary …

Schlieren Imaging Of A Supersonic Wind Tunnel, Caleb Townsend, Tayler S. Powell

Williams Honors College, Honors Research Projects

This project exemplifies Schlieren Imaging on a Supersonic Wind Tunnel. Schlieren Imaging allows one to visualize fluid flow by refracting light through a fluid. The Schlieren Imaging system denoted in this paper is used to visualize the shock waves of air onto a test section within a supersonic wind tunnel. This is done by directing a beam of light through a test section and then focusing the light onto a blade edge. This blade edge then breaks up the light beam so that the refractions, created by the pressure differences, are blocked by the knife edge which allows the pressure …

The Design Of The Payload System Of An Aircraft, Ryan Cooper

Williams Honors College, Honors Research Projects

The project group will design and build a system to unload packages for the Zips Aero Design Team's aircraft for the 2021-22 competition year.

Dirigible Anemometer Mount, Matthew Stanko

Williams Honors College, Honors Research Projects

Airships, like any other aircraft, require sensor inputs in order to fly. One type of sensor is the anemometer. This project outlines the development of a mounting system which would attach 2 ultrasonic anemometers to the bottom of an aircraft. The study follows the entire engineering process from requirement derivation through conceptual designs, testing, analysis, and verification. The details of this report are confidential and therefore cannot be disclosed.

Aerodynamics Wind Tunnel Lab, James Soroczak, Brett Preslar

Williams Honors College, Honors Research Projects

The goal of this project is to create a lab for an aerodynamics class with the purpose of exploring the effects of various physical features and aerodynamic conditions on a wing. The main area of study will be the effects on lift, drag, and moment. To best display these effects, an airfoil/wing to wind tunnel interface with variable physical characteristics will be designed. The various physical alterations will be implemented to show the effect each one has on lift, drag, and moment. These alterations will include different aspect ratios, removable winglets, and various lengths. The airspeed and angle of attack …

Concept Evaluation And Development Of A Novel Approach For Integration Of Turbogeneration, Electrification And Supercharging On Heavy Duty Engines, Satyum Joshi

Dissertations, Master's Theses and Master's Reports

While many technologies such as electrically assisted turbocharging, exhaust energy recovery and mild hybridization have already proven to significantly increase heavy-duty engine efficiency, the key challenge to their widespread adoption has been their cost effectiveness and packaging. This research specifically addresses these challenges through evaluation and development of a novel technology concept termed as the Integrated Turbogeneration, Electrification and Supercharging (ITES) system. The concept integrates a secondary compressor, a turbocompound/expander turbine and an electric motor through a planetary gearset into the engine cranktrain. The approach enables a reduced system cost and space-claim, while maximizing the efficiency benefits of independent technologies. …

Passive Intermodulation Under Different Spring Contact Conditions, Shengxuan Xia, Emmanuel Olugbade, Yuchu He, Yansheng Wang, Hanfeng Wang, Krishna Rao, Marco Poort, Haicheng Zhou, Warren Lee, Nicholas Mcdonnell, Jonghyun Park, Chulsoon Hwang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Modularized designs have been widely used in today's consumer electronic devices and flexible RF springs are used for electrical connections between the modules. In the meantime, aluminum alloy material becomes a common chassis option. It is well known that the oxidized chassis surface introduces a certain level of nonlinearity when contacted by the springs, as known as passive intermodulation (PIM). PIM is one of the well-known root causes of the RF desensitization (desense). This paper is focused on investigating the relationship between PIM and contact conditions of the springs, especially contact area. The PIM level behavior is explained mathematically by …

Fuel-Rich Hetero-/Homogeneous Combustion Of C3h8/O2/N2 Mixtures Over Rhodium, John Mantzaras, Ran Sui, Rolf Bombach

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The catalytic (heterogeneous) and gas-phase (homogeneous) combustion of C3H8/O2/N2 mixtures over rhodium was investigated experimentally and numerically at 5 bar and at fuel-rich equivalence ratios π = 2.0-3.5 relevant to propane Catalytic Partial Oxidation (CPO). In situ spatially-resolved Raman measurements of major gas-phase species concentrations and Planar Laser Induced Fluorescence (PLIF) of formaldehyde were applied in an optically accessible channel-flow reactor to monitor the catalytic and gas-phase processes, respectively, while accompanying 2D simulations were carried out with detailed hetero-/homogeneous chemical reaction mechanisms. Due to the high gas-phase reactivity of propane, homogeneous chemistry could not be ignored over most of the …

Regulation Of Dendrite-Free Li Plating Via Lithiophilic Sites On Lithium-Alloy Surface, Yufang He, Mengyun Zhang, Aiping Wang, Bo Zhang, Hiep Pham, Qiao Hu, Li Sheng, Hong Xu, Li Wang, Jonghyun Park, Xiangming He

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lithium (Li) deposition behavior plays an important role in dendrite formation and the subsequent performance of lithium metal batteries. This work reveals the impact of the lithiophilic sites of lithium-alloy on the Li plating process via the first-principles calculations. We find that the Li deposition mechanisms on the Li metal and Li22Sn5 surface are different due to the lithiophilic sites. We first propose that Li plating on the Li metal surface goes through the "adsorption-reduction-desorption-heterogeneous nucleation-cluster drop "process, while it undergoes the "adsorption-reduction-growth "process on the Li22Sn5 surface. The lower adsorption energy contributes to the easy adsorption of Li on …

Nanobubble Capillary Force Between Parallel Plates, Eric Bird, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Aggregation of Fine or Ultrafine Particles in Liquid Due to the Nanobubble (NB) Bridging Capillary Force is a Key Process for Many Industrial Applications. the Magnitude and Direction of the NB Capillary Force (NBCF) Are Directly Affected by the Geometry of the NB Gas Bridge between Two Adjoining Particles. Although the NBCF Can Be Accurately Measured using Experimental Techniques, It is Very Challenging to Monitor the Images of a NB Capillary Bridge in Nanoscale Spatial Resolution in NBCF Measuring Experiments. as a Result, the Capillary Force Model that Predicts the Dependence of the NBCF on the Geometry of the …

A Two-Layer Constellation Scheduling Approach For Imaging And Communication, Skylar Cox, Justin Whitaker, John Humble, Greg Droge

Space Dynamics Laboratory Publications

Spacecraft constellations continue to grow in numbers, capability, and sophistication, requiring in creased levels of automation to properly cooperate in achieving their objectives. This paper develops a constellation scheduling capability for collecting images of points of interest (POI) and communicating the imagery data through the constellation to established ground station terminals. Various levels of coordination are considered. First, satellites coordinate to avoid duplicate efforts for imaging POIs; second, ground stations only service a single satellite at a time for downlinking; and third, satellites may crosslink data within the constellation to enable a more timely delivery of high-valued information as well …