Aerospace Engineering Commons^™

Aerodynamic Characterization Of An Elliptical Fairing In The Wake Of A Bluff Body, Luis Amaya

Electronic Theses and Dissertations, 2020-2023

Aerodynamic optimization is a key step in designing planes, cars, and even buildings. Numerical modeling is used to automate the optimization process and can use different methods to iterate through designs. In this process, consideration of the starting design is paramount as a poor choice can use up computational time and effort. Often, these designs are made with the intention of being out in the open, for which studies on shape variations in freestream situations abound. However, for the case where an object must be placed in the wake of another, there is little research. The study presented here aims …

Theoretical And Experimental Application Of Neural Networks In Spaceflight Control Systems, Pavel Galchenko

Doctoral Dissertations

“Spaceflight systems can enable advanced mission concepts that can help expand our understanding of the universe. To achieve the objectives of these missions, spaceflight systems typically leverage guidance and control systems to maintain some desired path and/or orientation of their scientific instrumentation. A deep understanding of the natural dynamics of the environment in which these spaceflight systems operate is required to design control systems capable of achieving the desired scientific objectives. However, mitigating strategies are critically important when these dynamics are unknown or poorly understood and/or modelled. This research introduces two neural network methodologies to control the translation and rotation …

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, …

Ground To Air Testing Of A Fused Optical-Radar Aircraft Detection And Tracking System, Chester V. Dolph, Thomas Lombaerts, Evan Kawamura, Corey Ippolito, Vahram Stepanyan, Khan M. Iftekharuddin, George Szatkowski, Robert G. Mcswain, Chris Morris, Mahyar R. Malekpour

Electrical & Computer Engineering Faculty Publications

Onboard detection and tracking capability are integral to the sensing component in collision avoidance systems needed to safely operate autonomous urban air taxis and small Unmanned Aircraft Systems. Ground-based validation of detection and tracking systems is an important milestone towards the end goal of real-time collision avoidance using onboard sensors and algorithms. In this work, we evaluate three Extended Kalman Filter (EKF) based fusion trackers with radar and vision detection inputs, and compare them with baseline trackers for each sensor type. Performance is assessed using field collected data of ground to air test flights with the sensors co-located on a …

Developing Reactive Distributed Aerial Robotics Platforms For Real-Time Contaminant Mapping, Joshua Ashley

Theses and Dissertations--Electrical and Computer Engineering

The focus of this research is to design a sensor data aggregation system and centralized sensor-driven trajectory planning algorithm for fixed-wing aircraft to optimally assist atmospheric simulators in mapping the local environment in real-time. The proposed application of this work is to be used in the event of a hazardous contaminant leak into the atmosphere as a fleet of sensing unmanned aerial vehicles (UAVs) could provide valuable information for evacuation measures. The data aggregation system was designed using a state-of-the-art networking protocol and radio with DigiMesh and a process/data management system in the ROS2 DDS. This system was tested to …

Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

In lieu of an abstract, this is an excerpt from the first page.

Microfluidics has seen a remarkable growth over the past few decades, with its extensive applications in engineering, medicine, biology, chemistry, etc [...]

Aerodynamic Analysis Of Damage State Missiles Using Overset Meshing Techniques For Application To Computational Fluid Dynamics Simulation, Jonathan A. D'Alessio

Graduate Theses, Dissertations, and Problem Reports (ETD)

Significant research over the years has aimed to redefine the flight capabilities of aircraft after sustaining structural damage to critical components. Flight survivability and controllability are key areas of concern when designing fault-tolerant flight control systems to handle a wide range of potential scenarios. However, there is a lack of research on the impact of physically damaged missile systems. Missile counter-defense and intercept capabilities have become more advanced as the United States has focused heavily on these areas over the years. Damaged missiles due to a kinetic intercept capability present an opportunity for analysis of the post-damage implications on flight …

Effect Of Freestream Noise On Hypersonic Crossflow-Induced Boundary-Layer Transition, Andrew Bustard, Thomas J. Juliano, Harrison B. Yates, Mark Noftz, Joseph Jewell

Publications

Between the windward and leeward rays, boundary-layer transition on cones at angle of attack in hypersonic flow is dominated by the crossflow instability [1, 2], wherein stationary and/or traveling crossflow vortices develop and can breakdown into turbulence [3]. Stationary crossflow modes are caused by surface roughness or any other steady forcing and produce disturbances that are fixed in place on the surface [3–6]. Stationary vortices create a generalized inflection point in the velocity profile that is inviscidly unstable [7]. This distorted mean flow develops secondary instabilities, whose growth and breakdown is one path to turbulence [8–10]. Traveling crossflow modes are …

On The Implementation And Further Validation Of A Time Domain Boundary Element Method Broadband Impedance Boundary Condition, Fang Q. Hu, Douglas M. Nark

Mathematics & Statistics Faculty Publications

A time domain boundary integral equation with Burton-Miller reformulation is presented for acoustic scattering by surfaces with liners in a uniform mean flow. The Ingard-Myers impedance boundary condition is implemented using a broadband multipole impedance model and converted into time domain differential equations to augment the boundary integral equation. The coupled integral-differential equations are solved numerically by a March-On-in-Time (MOT) scheme. While the Ingard-Myers condition is known to support Kelvin-Helmholtz instability due to its use of a vortex sheet interface between the flow and the liner surface, it is found that by neglecting a second derivative term in the current …

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 …

Experiences During The Implementation Of Two Different Project-Based Learning Assignments In A Fluid Mechanics Course., Orlando Ayala, Kristie Gutierrez, Francisco Cima, Julia Noginova, Min Jung Lee, Stacie Ringleb, Pilar Pazos, Krishnanand Kaipa, Jennifer Kidd

Engineering Technology Faculty Publications

There is growing evidence of the effectiveness of project-based learning (PBL) in preparing students to solve complex problems. In PBL implementations in engineering, students are treated as professional engineers facing projects centered around real-world problems, including the complexity and uncertainty that influence such problems. Not only does this help students to analyze and solve an authentic real-world task, promoting critical thinking, but also students learn from each other, learning valuable communication and teamwork skills. Faculty play an important part by assuming non-conventional roles (e.g., client, senior professional engineer, consultant) to help students throughout this instructional and learning approach. Typically 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 …

Drone Cage Design And Implementation To Enable Small Drone Architecture Testing, Marco Fagetti, Emily M. Suh

Undergraduate Student Works

Geometric mechanics is a dynamical formalism that allows for simultaneous treatment of rotational and translational motion without the drawbacks of attitude parameterization sets. While geometric mechanics is well suited to deal with full six degree-of-freedom motion or significant position-attitude coupling, this formalism has yet to be extensively applied to hardware systems. The broader research goals of this work aim to prove the practical viability of this theoretical framework by applying it to a class of Crazyflie drones, which are frequently used to assess Guidance, Navigation, and Control schemes. To efficiently achieve these goals, a reliable, collapsible drone cage is required …

Impact Of Covid-19 On Aviation-Wildlife Strikes Across Europe, Isabel C. Metz, Marta Giordano, Dionysios Ntampakis, Marianna Moira, Anneke Hamann, Rosanne Blijleven, Jürgen J. Ebert, Alessandro Montemaggiori

Human–Wildlife Interactions

Collisions between aircraft and wildlife (i.e., wildlife strikes) pose a serious threat toward the safety of aircraft, its crew, and passengers. The effects of COVID-19 related travel restrictions on wildlife strikes are unknown. With this study, we aim to address this information gap by assessing the changes of wildlife hazard management performance across European airports during the lockdown period (e.g., period of reduced operations and borders closure in spring 2020). We also sought to raise awareness of the importance of wildlife strike prevention in times of reduced operations. The objective of our study was to compare wildlife strike data before …

Jointly-Learnt Networks For Future Action Anticipation Via Self-Knowledge Distillation And Cycle Consistency, Md Moniruzzaman, Zhaozheng Yin, Zhihai He, Ming-Chuan Leu, Ruwen Qin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Future action anticipation aims to infer future actions from the observation of a small set of past video frames. In this paper, we propose a novel Jointly learnt Action Anticipation Network (J-AAN) via Self-Knowledge Distillation (Self-KD) and cycle consistency for future action anticipation. In contrast to the current state-of-the-art methods which anticipate the future actions either directly or recursively, our proposed J-AAN anticipates the future actions jointly in both direct and recursive ways. However, when dealing with future action anticipation, one important challenge to address is the future's uncertainty since multiple action sequences may come from or be followed by …

Additive Manufacturing Of Continuous Carbon Fiber-Reinforced Sic Ceramic Composite With Multiple Fiber Bundles By An Extrusion-Based Technique, Ruoyu Chen, Adam Bratten, Joshua Rittenhouse, Ming-Chuan Leu, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Due to the high cost, complex preparation process and difficulty in structural design, the traditional methods for carbon fiber reinforced SiC ceramic composite preparation have great limitations. This paper presents a technique for the additive manufacturing multiple continuous carbon fiber bundle-reinforced SiC ceramic composite with core-shell structure using an extrusion-based technique. A conventional nozzle system was modified to print simultaneously a water based SiC paste with continuous carbon fibers. Different levels of binder contents were investigated to optimize the stickiness, viscosity, thixotropy and viscoelasticity of the paste. After sintering, SiC whiskers were generated on the surface of fiber, which is …

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 …

Two-Level Targeter Convergence Study For Collinear Libration Point Spacecraft Formations, Donna Jennings, Henry J. Pernicka

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Spacecraft formation flying has attracted an increasing amount attention over the past several decades including a growing interest in relative motion at the collinear lib ration points. This current work builds on previous efforts by further developing and characterizing a two-level targeting (TLT) algorithm used to determine relative motion at lib ration points by performing a convergence study. A parametric study was conducted to identify the sensitivity of the algorithm to a variety of inputs and constraints. The parametric study revealed that the two-level targeting algorithm convergence properties significantly improve when using a higher order initialization estimate. The size of …

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 …

Direct Numerical Simulation Of Acoustic Disturbances In A Hypersonic Two-Dimensional Nozzle Configuration, Nathaniel Hildebrand, Meelan M. Choudhari, Cole P. Deegan, Junji Huang, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations (DNS) are performed to study acoustic radiation in a quasi-two-dimensional nozzle with two independents spatially evolving turbulent boundary layers with an edge Mach number of 6. The emphasis of this work is to compare the radiated pressure fluctuations in a geometrically confined environment with those radiated from a single wall in an unconfined setting. The boundary-layer profile of the rms pressure fluctuation scaled by the mean shear stress at the wall is found to be in good agreement with prior flat-plate calculations at similar conditions. However, the normalized rms pressure fluctuation within the freestream p region is …