Engineering Commons^™

Adiabatic And Overall Effectiveness Superposition Theory For Upstream Phantom Cooling On A Film Cooled Leading Edge, Nathaniel J. Stout

Theses and Dissertations

Film cooling experimentation aims to improve the cooling performance while minimizing the amount of coolant flow redirected from the compressor. The coolant flow that is used for film cooling reduces the maximum thrust any gas turbine engine can produce. Finding creative ways to improve cooling performance without increasing the amount of coolant used, like phantom cooling, is essential for the gas turbine industry to improve engine performance while increasing turbine components’ lifespan. Phantom cooling refers to any secondary cooling effect that propagates downstream from its original cooling application to cool subsequent turbine components. Phantom cooling is actively gaining more attention …

Heterogeneous Boid Swarm Performance Under Environmental And Neighbor Communication Link Variability, Jonathan C. Oxborrow

Theses and Dissertations

Artificial swarms are of growing interest in numerous fields and use cases. As their utilization increases drones and robots with different capabilities will be required to coordinate for task completion thus creating heterogeneous swarms. Swarm individuals generally communicate with all neighbors inside their sensor range generating a significant amount of message traffic. Previous research of a heterogeneous group in a non-physical environment has shown that restricting communication to only one neighbor of each different capability maintained performance. This work applies that finding to a heterogeneous boid swarm with the addition of varied environmental conditions. The swarm is comprised of three …

Fatigue Behavior Of An Advanced Sic/Sic Composite With An Array Of Small Cooling Holes At 1200°C, Tess K. Panchyshyn

Theses and Dissertations

Tension-tension fatigue behavior of an advanced melt-infiltrated (MI) silicon carbide/silicon carbide (SiC/SiC) composite was evaluated, and basic tensile properties measured, at 1200°C in laboratory air.  The composite consists of a melt-infiltrated SiC matrix reinforced with laminated Hi-Nicalon Type-S fibers woven in a 5-harness satin weave. The Hi-Nicalon-S fiber preforms were coated with a boron nitride (BN) fiber coating by chemical vapor infiltration (CVI). The melt-infiltrated matrix was consolidated by combining CVI-SiC with SiC particulate slurry and molten silicon infiltration. The finished ceramic matrix composite (CMC) had a fiber volume fraction of 33%. Additionally, the effect of multiple small holes on …

Creating And Analyzing Space Vehicle Seit/Pm Factors, Jordan A. Bosco

Theses and Dissertations

The Department of Defense relies on accurate cost estimation to inform budget decisions. Beyond being a critical component of the Defense Acquisition System, cost estimation is a legal requirement in the budgeting process. Cost analysts, therefore, have both a fiduciary and statutory responsibility to produce realistic estimates. Among the many elements of a space system cost estimate is Space Vehicle Systems Engineering, Integration & Test, and Program Management (SEIT/PM). While existing factors aid in estimating SEIT/PM, Space Systems Command is interested in research in alternatives to the current methods and crosschecks for those methods. This study develops a set of …

Deep Reinforcement Learning For Leo Satellite Grouping, James E. Minteer

Theses and Dissertations

This research investigates jamming evasion using DRL to provide an autonomous solution that repositions a geostationary satellite experiencing directed, terrestrial based jamming. Second, this thesis applies DRL to an area of research for LEO satellite constellations, user grouping, using a portion of an Air Force Research Lab reinforcement learning framework. As LEO satellites orbit the earth, they must constantly re-evaluate not only which users they are able to connect to, but on which of its multiple beams. This model succeeds in finding a balance between maximizing signal strength and minimizing overhead from switching user assignments, all while requiring fewer costly …

Choosing Robust Leadership: Encompassing The Best-Of-N Model And Swarm Intelligence Optimization For Heterogeneous Multiple Autonomous Unmanned Aerial Vehicle Systems, Kudamuhandiramlage Harith Kolitha Warnakulasooriya

Shelby Hall Graduate Research Forum Presentations

Presentation slides for a presentation given at the 1st annual Shelby Hall Graduate Research Forum at the University of South Alabama.

Thermal Stability Analysis Of Aqueous Ionic Amines For Sustainable Co2 Capture, Li Hua Zang, Keegan Everitt, Kevin West, Brooks D. Rabideau, Breanna Dobyns, James Davis

Shelby Hall Graduate Research Forum Posters

In closed air cabin atmospheres such as those of spacecraft, CO₂ accumulation jeopardizes crew respiratory function and may gradually affect sensitive equipment, making effective air revitalization critical. Traditional CO₂ capture methods like monoethanolamine (MEA) efficiently capture CO₂ but suffer from high volatility, leading to solvent loss and unpleasant odor, as well as corrosion and degradation, requiring frequent replacement. These flaws demand eco-friendly, durable alternatives. This study addresses these limitations by exploring a series of aqueous ionic amines (AIAs), salts similar to MEA in CO₂ capture efficiency but with improved thermal stability—crucial for preventing degradation under high regeneration temperatures and prolonged …

Improving Smartphone Gnss Jammer Localization With Cloud-Based Environmental Occlusion Modeling, Glenn H. Jones

Theses and Dissertations

The advancement of Global Navigation Satellite System (GNSS) technology in modern smartphones has made these devices pervasive in both civilian and military applications. Although smartphone GNSS chipsets are more susceptible to jamming and spoofing than military grade hardware, smartphone networks offer an underutilized opportunity to detect and mitigate threats to position, navigation, and timing (PNT) services essential to the Department of Defense (DoD) and civilian first responders. Traditional methods for geolocating ground-based jamming sources using smartphone GNSS often fail in environments with dense vegetation or significant occlusions, resulting in substantial localization errors.

A Multi-Objective Reinforcement Learning Framework For Title Autonomous On-Orbit Inspections, Austin C. Reynolds

Theses and Dissertations

The rapidly evolving landscape of space operations necessitates dynamic and autonomous systems to address complex challenges such as Resident Space Object (RSO) inspections. This research explores the application of a Multi-Objective Reinforcement Learning (MORL) framework to rendezvous and proximity operations (RPO), enabling agents to balance conflicting objectives like time efficiency, fuel conservation, and information gain. Unlike traditional reinforcement learning, MORL allows dynamic reweighting of objectives without retraining, offering adaptability and efficiency in multi-objective environments. The study demonstrates MORL's capabilities through custom 2D and 3D simulations of Hill-Clohessy-Wiltshire (HCW) environments and comparing its performance to traditional RL in RPO scenarios. Tasks …

Lethality And Survivability Of Autonomous Self-Sensing Uavs, Jeffrey T. Wilson

Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) have seen increased usage over the past two decades during the Global War on Terrorism (GWOT), operating in low-risk environments against dispersed enemies with minimal counter-drone capabilities. However, as the U.S. military shifts focus to Multi-Domain Operations (MDO) and Large Scale Combat Operations (LSCO), UAVs face significantly higher risks, including frequent and successful attacks, as well as the exploitation of their technology. Battle damage assessment (BDA) is not new; however, autonomous self-assessment by UAVs represents a novel advancement. Currently, UAV BDA relies on manual inspection, requiring approximately eight hours per drone. By adopting self-sensing technology, UAVs …

Utility Of Self-Sensing Damage Technology Through A2/Ad Drone Combat Simulation, Sidhanth Venkatasubramaniam

Theses and Dissertations

Since the introduction of the first unmanned aerial vehicle (UAV), UAVs have consistently improved in capability and versatility. The ability to perform military operations without the risk of losing human life is crucial for the United States military. The trade-off for this versatility is cost, and several ongoing research efforts are being made to improve UAV mission success and the lifespan of UAVs. An area of research that falls under the categories mentioned is self-damage detection. The Air Force Research Laboratories (AFRL) are developing a capability to enable a UAV to assess airframe damage, enabling real-time determination of damage potentially …

Proof Of Concept: Using Uas Technology To Accomplish Aerial Roof Inspections, Madison R. Fanning

Theses and Dissertations

With the growing use of simulation across industries, the digital twin remains an underexplored research area, particularly in emergency management and response. Its real-time updating capability is often overlooked due to the misconception that "digital twin" is merely a complex term for simulation. This paper highlights its distinctiveness through an evasion exercise involving two independent entities in a collocated environment. Using a highly integrated virtual environment (HIVE) and internet of things (IoT) devices, we link the physical system with an analytical simulation, demonstrating the impact of lag times in high-pressure scenarios. The computational model leverages agent-based modeling (ABM) and discrete-event …

Best Estimate Reconstruction Of The Control Profile For A Maneuvering Reentry Vehicle, Justin R. Evans

Theses and Dissertations

Astrodynamic reentry is an increasingly important flight regime as countries around the world develop new spacecraft and weapons. A design of interest is that of hypersonic glide vehicles with the ability to maneuver in the atmosphere. As these vehicles become more common across the world, it has become advantageous to track foreign reentry tests in order to determine capabilities. While current observation techniques may allow position and velocity to be tracked across the trajectory, orientation of the vehicle is not always observable. The ability to find vehicle orientation across time gives insight into the performance characteristics of the vehicle. This …

Extension Of The Circular Restricted N-Body Problem (Crnbp) To Varying Multi-Body Gravitational Systems, Annika J. Gilliam

Theses and Dissertations

Multi-body dynamical models are a valuable tool used to examine certain aspects of spacecraft orbital mechanics by applying assumptions to restrict the problem. The Circular Restricted Three-Body Problem (CR3BP), one of these dynamical models, has been examined extensively in the last few decades; however, this model is not sufficient in the case of more than two massive celestial bodies gravitationally affecting a spacecraft. A novel model called the Circular Restricted N-Body Problem (CRNBP) is studied in this research as an alternative to the traditional CR3BP where necessary. A variety of systems are examined in this thesis, including the Jovian, Saturnian, …

Approximating Three-Body Trajectories With A Knot Theory Inspired Model For Orbit Generation And Determination, Mason R. Mill

Theses and Dissertations

This thesis explores a novel approach to approximating three-body trajectories using a knot theory-inspired model for orbit generation and determination. Traditional methods for solving the Circular Restricted Three-Body Problem (CR3BP) rely on numerical integration and correction schemes to generate trajectories, often requiring iterative refinements. This research investigates the application of knot theory principles—such as torus knots, Alexander polynomials, and Reidemeister moves—to categorize and model complex orbital trajectories in the CR3BP. By leveraging these mathematical tools, the study aims to enhance trajectory prediction, orbit determination, and mission planning for spacecraft operating in the cislunar environment. The results demonstrate that knot theory …

Analyzing And Mapping Hypersonic Cruise Vehicle Maneuvers, Kyle T. Monsma

Theses and Dissertations

This thesis develops a computational framework for analyzing the stability, control, and maneuverability of hypersonic cruise vehicles using surrogate modeling and trajectory propagation techniques. A polynomial ridge regression approach is implemented to create a continuous aerodynamic model from discrete force-moment data, enabling rapid stability and control assessments across Mach and altitude ranges. Vinh’s equations of motion are utilized to account for Earth’s curvature and gravitational effects, refining trajectory analysis for maneuver feasibility studies. Energy maneuverability diagrams, turn rate charts, and short-period stability metrics are generated to visualize flight performance constraints and dynamic stability characteristics. The results highlight the impact of …

Investigation Of The Convective Heat Transfer Driving Potential For Hypersonic Flows, Roderick A. Mills

Theses and Dissertations

Accurately determining adiabatic wall temperature is critical for characterizing surface heating in hypersonic flows. The differences between adiabatic wall temperature and stagnation temperature for Mach 6 flow are examined. A two-dimensional explicit finite difference scheme was developed to analyze heat transfer within an angled wedge and to assess the applicability of the classical semi-infinite solid solution to the Fourier Heat Equation for estimating adiabatic wall temperature and convective heat transfer coefficients. Experimental surface temperature data were extracted from infrared thermography obtained during Mach 6 wind tunnel tests, and the semi-infinite solid solution was applied to estimate the adiabatic wall temperature. …

Thin-Filament Pyrometry In A Rotating Detonation Engine, Theodore B. Guetig

Theses and Dissertations

Rotating Detonation Engine (RDE) proves beneficial by creating a pressure rise across the combustor rather than a pressure drop seen in traditional aircraft combustors. Coupled with this high pressure is a high temperature in the detonation engine that is difficult to measure as it varies spatially and temporally. Thin-Filament Pyrometry (TFP) was performed on a 6-in RDE to measure these high temperatures. Temperature profiles were obtained over a variety of mass flows, equivalence ratios, and different axial locations within the RDE providing insight into the mixing process and where the heat release occurs. Successful determination of these temperature profiles within …

Design And Evaluation Of A Deployment Mechanism For A Space-Based Origami Mirror In Cubesat Missions, Arturo Luna

Theses and Dissertations

The space environment’s suboptimal lighting conditions and eclipse periods impede inspection and on-orbit servicing missions. To abate this problem, the Air Force Institute of Technology (AFIT) launched the Mirror Illumination for Reconnaissance and Rendezvous of Orbital Resident Systems (MIRRORS) initiative. This initiative provides augmented illumination to resident space objects (RSOs) by reflecting the sun’s rays from a mirror satellite. Leveraging origami-inspired designs for compact packaging, AFIT developed a cube origami flasher mirror constructed from aluminum panels that unfolds passively via Nitinol hinges. This research investigates the necessary deployment and panning mechanisms for a dynamic, space-based origami mirror to advance the …

An Analytical Approach In Solving A Two-On-One Pursuit Evasion Differential Game With Fast Evader And No-Point Capture, Nathan T. Morrow

Theses and Dissertations

This paper is concerned with a co-planar pursuit-evasion scenario where two Pursuers (P) are after an Evader (E). The players are holonomic/can turn on a dime and their speeds, V_P and V_E, are constant, but the evader is faster than the pursuers, that is, the speed ratio parameter μ =  V_E/V_P > 1. The Pursuers are endowed with a circular capture disc whose radius l > 0. A differential game (DG) with three states and one parameter is addressed through geometric and analytical methods where a partial solution is outlined and visualized. The game is split …

Solid State Transformer Controls For Mitigation Of E3a High-Altitude Electromagnetic Pulse Insults, Connor A. Lehman, Rush D. Robinett, Wayne Weaver, David G. Wilson

Michigan Tech Publications

This paper explores the use of a solid state transformer (SST) to mitigate the 𝐸3𝐴 component of a high-altitude electromagnetic pulse (HEMP) insult using external energy storage optimal control techniques. In lieu of conventional passive blocking devices or feedback-controlled energy storage devices, a novel implementation of Hamiltonian error tracking is utilized to develop a feedback control law for the variable converter ratio in an SST. The findings of the simulations performed in this paper suggest that additional energy storage is not necessary to protect an individual load from a HEMP insult. The simulations performed examine the response of a single-phase …

Stanag 4575 Cst M35, Will Scheirer, Lee Sublett, George Weiss, Tina Howell, Ben Hill, Jared Sanders

Space Dynamics Laboratory Publications

General Information

➢ Provides a standardized “direct data download” capability from any NADSI compliant ISR data acquisition recorder to a compliant ground station

➢ STANAG 4575 Ed.4 became a mandated DISR standard for US DoD organizations on 24 April 2018; STANAG 4575 Ed. 5 is currently under JCGISR silence procedure until 14 February

➢ Magnetic Disk, Solid State, Complete Units, or Removable Media Modules (RMMs); Non-proprietary Directory and File Structure

➢ Based On Commercial Gigabit Ethernet Standards TCP/IP and Fiber Channel

Ongoing Efforts

➢ Working NADSI Ed.5 implementation with various national and international industry partners and manufacturers

➢ Further NADSI …

Quality Evaluation For Colored Point Clouds Produced By Autonomous Vehicle Sensor Fusion Systems, Colin Schaefer, Zeid Kootbally, Vinh Nguyen

Michigan Tech Publications

Perception systems for autonomous vehicles (AVs) require various types of sensors, including light detection and ranging (LiDAR) and cameras, to ensure their robustness in driving scenarios and weather conditions. The data from these sensors are fused together to generate maps of the surrounding environment and provide information for the detection and tracking of objects. Hence, evaluation methods are necessary to compare existing and future sensor systems through quantifiable measurements given the wide range of sensor models and design choices. This paper presents an evaluation method to compare colored point clouds, a common fused data type, among two LiDAR-camera fusion systems …

Flight Crew And Aviation Sustainability, Eva Maleviti

Publications

Sustainable Development

The concept of sustainable development was defined in the World Commission on Environment and Development’s (WCED) 1987 Brundtland Report ‘’Our Common Future’’. The Brundtland Commission aimed to help world nations towards sustainable development. Then, sustainable development became an essential concept in the vocabulary of politicians, practitioners, and planners.

Metaheuristic Techniques To Optimize Trajectory Planning Of Uav Swarms: Enhancing Data Acquisition In Wireless Sensor Networks, Nada Ali Mohamed Ahmed Ahmed

Theses and Dissertations

Unmanned aerial vehicles (UAVs) have become increasingly integrated into various applications due to their cost-efficiency, rapid deployment, flexible maneuvers, and enhanced performance. This has led to the development of a new field called UAV-assisted Wireless Sensor Networks (U-WSNs), which focus on data routing, network performance optimization, and planning UAV trajectories between sensor nodes in wireless sensor networks. In this thesis, a new framework has been proposed to manage a swarm of UAVs cooperatively serving large-scale wireless sensor networks. The framework consists of three optimization problems: distributing sensor nodes among UAVs, finding optimal trajectories in the presence of obstacles, and performing …

The Future Of Aviation: Becoming An Evtol Pilot – Faa’S New Regulations Open Up Career Opportunities, Sarah Nilsson

Publications

As the aviation industry stands on the brink of a revolutionary change, aspiring pilots are increasingly drawn to the exciting prospect of flying electric Vertical Takeoff and Landing (eVTOL) aircraft. The allure of this cutting-edge technology has many asking: “How does one become an eVTOL pilot in the United States?” This question opens up a cascade of inquiries about the future of flight training, the certification process and the transition for existing pilots into this new realm of aviation like:

• What will the flight training curriculum look like for eVTOL aircraft?

• Who will be the pioneering Certified Flight …

Stabilizing A Bio-Inspired Rotating Empennage Fighter Aircraft In Multiple Trim Scenarios, Benjamin C. Moulton, Matthew W. Harris, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

This paper considers the problem of stabilizing a bio-inspired fighter aircraft at its Air Combat Maneuver Condition in steady level and coordinated-turning flight. The aircraft equations of motion are linearized, and an infinite-horizon linear quadratic regulator design is conducted. The open-loop system is unstable in the short period and Dutch roll modes. This is mitigated in the closed-loop system, which is analyzed in the time and frequency domains. Included in the simulation dynamics are first-order actuator models, actuator deflection limits, and actuator rate limits. These are particularly important for this bio-inspired aircraft because control actuation requires rotation of the empennage, …

The Problem Of Reducing The Wave Resistance Of Blunt Bodies At Supersonic And Hypersonic Velocities, Oleksandr M. Shyiko, Olexii A. Оbukhov

Journal of Aviation Technology and Engineering

A new method for reducing the aerodynamic wave drag of blunt bodies in supersonic and hypersonic flows is considered. The method is based on the destruction of the detached head shock wave by placing a family of thin needle elements of a cone-shaped or cylindrical type on the blunt surface. This qualitatively changes the gas-dynamic flow pattern and leads to a new positive quantitative effect. The bow shock wave breaks up into a series of local interacting shock waves of lower intensity, which leads to a decrease in the wave drag of the streamlined body. Variants of hemispherical blunting of …

Circular Dichroism In Achiral Metasurfaces Induced By Spatially Selective Coupling With Molecules, Baojuan Han, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Achiral metasurfaces with near-field optical chirality have attracted great attention in molecular sensing and chiral emission control. Here, the circular dichroism (CD) response of an achiral metasurface induced by spatially selective coupling with polymethyl methacrylate (PMMA) molecules is demonstrated. A designed achiral metasurface with a V-shaped resonator exhibits large optical chirality with a strongly dissymmetric distribution under circular polarization. By introducing a PMMA molecule layer on top of the metasurface, which covers the area with large optical chirality, CD in absorption of 0.38 and a dissymmetric factor of optical chirality gc of 0.16 are obtained. Furthermore, an analysis of the …

Optimization Of The Cross-Section Of Generic Flexible Bridges, Manal Kamal Zaki, Mina M. Helmy, Mark M. Tawadros

Journal of Engineering Research

This paper investigates the behavior of flexible bridges prone to aerodynamic instabilities due to wind. Optimal cross-sections that reduce aerodynamic forces are recommended. This is achieved by studying a variety of bridge sections with different widths of upper and lower sloping edges in addition to studying the upper and lower cramps of the deck. The wind velocities are also parameterized. Computations are developed based on the powerful computational fluid dynamics (CFD) method known as FLUENT and embedded in ANSYS software. For parametric study, a design of experiments (DOE) is performed based on the response surface methodology (RSM) combined with the …