Engineering Commons^™

Self-Regulated Thermal Management With Shape-Memory Alloy Torsional Tubes, Paula Sanjuan Espejo

Doctoral Dissertations and Master's Theses

The need for dynamic thermal management that adapts to varying system needs and requirements is a growing topic of interest in different engineering disciplines, most prominently aerospace and electronics. This demand for improved thermal management systems comes from the general increase of system efficiencies leading to an increase in component energy density. Shape-memory alloy actuators, which respond with a mechanical shape recovery to variations in temperature, can be used as self-regulated thermal management actuators that are able to respond to environmental thermal changes autonomously. In this dissertation, modeling and experimental analysis of a two-way shape-memory effect trained SMA torsional tube …

Embeddable Multi-Material Wireless Micro-Sensors Utilizing Additive Manufacturing And Enhanced Microstructure, Nicholas Reed

Doctoral Dissertations and Master's Theses

The development of embeddable, multi-material wireless microsensors offers transformative potential for structural health monitoring (SHM) in aerospace applications. This work integrates additive manufacturing (AM) techniques with advanced microstructural design to produce flexible, high-resolution sensors that can be directly embedded into polymer substrates. By utilizing the vat photopolymerization process, customized embedded sensors are seamlessly integrated into polymer AM structures. These sensors are then continuously refined, targeting increases in performance, both internal and external. Microstructural enhancements are explored to modify the rheological properties of the fabricated embedded sensing channels and enhance the adhesive bonding between the embedded sensor and the AM structure. …

Reusing Materials In The Aerospace Industry, Lama Alanazi, Burtegeljin Gombosuren, Byhalia Jewett

Beyond: Undergraduate Research Journal

This research explores the material recycling methods used by the aerospace industry, particularly in comparison to the reusability of aerospace materials and with the objective to find uses for recycled materials from aircraft. Through an analysis of various other material mitigation methods, it is apparent that the physical degradation of materials after they go through recycling processes and the cost of recycling are the most prominent issues holding the aerospace industry back from being able to recycle aircraft up to 100%. From a comparison of physical characteristics of materials after reprocessing, several materials were found to meet industry standards, while …

Examining The Impact Of Stress On Collegiate Flight Students, Shivanee D. Cannon-Patron

Beyond: Undergraduate Research Journal

Stress may negatively affect the timely completion of a student pilot's flight training. A student pilot influenced by stress may be subject to what is known as "falling behind the aircraft," a condition that constantly requires minor interventions from their flight instructor. This lack of situational awareness and decreased performance may inadvertently cause the student pilot to repeat the flight lesson, increasing the time spent in the training course.

Evaluating The Physiological Effects Of A Spacesuit While Performing Cpr, Marielle Lenehan

Beyond: Undergraduate Research Journal

Limited research exists on the challenges of performing cardiopulmonary resuscitation (CPR) while wearing a spacesuit/pressure suit; but, during a space mission or following spacecraft egress, astronauts may need to perform Basic Life Support (BLS) on a crewmember. BLS consists of CPR and External Chest Compressions (ECC). In an emergency, astronauts may not have time to remove their intravehicular (IVA) spacesuits/pressure suits or wait for their heart rates to return to resting conditions and, therefore, would have to perform CPR while physically exerted. This study sought to evaluate the physiological exertion on rescuer performance while performing ECCs over 6 minutes while …

Leveraging Artificial Intelligence In Education To Drive Cross-Sector Innovation, Brent Terwilliger, John Faraca

Publications

As artificial intelligence (AI) reshapes educational practices, particularly in technical fields such as uncrewed systems, robotics, and aviation/ aerospace, its integration raises promise and complexity. This exploratory study features an investigation of the impact AI tools adoption has on instruction, curriculum support, and workforce preparation, with a focus on online learning environments. Drawing from pilot survey data across aviation and aerospace education stakeholders and hands-on evaluation of AI video production platforms, findings reveal diverse applications, perceived benefits, and critical concerns, including ethical, pedagogical, and institutional challenges. Additionally, the analysis explored how AI-enabled education intersects with broader industry and government innovation …

Characterization Of A Magnetically Contained Hot Filament Plasma Source With A Wide-Sweeping Langmuir Probe, Jonas Rowan

Doctoral Dissertations and Master's Theses

Ionospheric plasma research in the Space and Atmospheric Instrumentation Laboratory’s Space Plasma Chamber has been hindered by the lack of a suitable plasma diagnostic instrument and understanding of its hot-filament plasma source. This thesis describes efforts made to remedy both problems. A wide-range Sweeping Langmuir Probe was developed with a ±35 V sweeping range to fully analyze ion and electron saturation regions in the entire IV curve. A method was derived to estimate the chamber source’s filament temperatures. The new Langmuir probe was integrated into a refurbished automated system designed in Python to measure plasma parameters for various chamber conditions, …

Solar Sailing Adaptive Control Around The Earth-Moon Lagrange Point L4 For Stellar Observations, Luis Mendoza Zambrano

Doctoral Dissertations and Master's Theses

To expand our knowledge about the influence of the Sun in the cislunar region, as well as our understanding of shocks due to Coronal Mass Ejections and large coronal magnetic reconnection, a solar sailing approach is proposed to separately capture lunar occultations and observe the solar corona from L₄ of the Earth-Moon system. Single and multiple shooting techniques are described along with a pseudo arc-length continuation method for preliminary orbit design. Periodic orbits in the vicinity of L₄ are obtained in the context of the Earth-Moon circular restricted three-body problem (CR3BP) and the Sun-Earth-Moon bi-circular restricted four-body problem …

Satellite Reorientation Using Reinforcement Learning Under Unknown Attitude Failure, Matthew Willoughby

Doctoral Dissertations and Master's Theses

This study presents a reinforcement learning (RL) approach for reestablishing communication with deep-space satellites under unknown attitude determination and control system (ADCS) failures. When traditional fault-tolerant control methods cannot restore signal, the proposed RL controller acts as a last-resort measure by autonomously reorienting the satellite’s antenna toward Earth while charging the battery via solar panels. A generic reward function, designed for the RL-based method, enables the controller to adapt to diverse failure scenarios, including severe actuator noise, misalignment, and complete actuator failure. Simulations are conducted in the Basilisk environment and trained with the tonic framework and demonstrate ranging capabilities of …

Evaluation Of Chloride Diffusion In Concrete Using Bulk Diffusion Test And Scanning Electron Microscopy, Payton Davis

Doctoral Dissertations and Master's Theses

Reinforced concrete is one of the most widely used construction materials in the world with many bridges and other major infrastructure consisting of such structural elements. A primary concern impacting the durability of concrete is chloride penetration in aggressive environments such as marine or coastal areas. In such environments, chloride ions can penetrate into the pores of concrete leading to the corrosion of embedded steel reinforcement which compromises the structural integrity of concrete. To investigate the issue, a comprehensive experimental program was designed and implemented which involved the preparation and testing of 31 different concrete mixes, each incorporating varying proportions …

Utilizing Augmented Reality For Immersive Space Mission Design, Joseph Anderson

Doctoral Dissertations and Master's Theses

Designing spacecraft mission trajectories is a complex, tedious, and stringent process that requires a strong background in astrodynamics and programming due to the complex dynamical environment of space. The current 2D visualization methods for displaying these geometrically abstract trajectories make it difficult to understand the true nature of more complex orbits. Advancements in immersive headsets and their intuitive interaction capabilities make them ideal for solving and understanding 3D problems that require complex spatial representations, revealing an innovative and unique opportunity for the astrodynamics and space mission planning field. This effort covers the development of an immersive space mission design tool …

Improving Erosion Resistance And Revegetation Of Wildfire-Altered Soils Using Microbial Induced Calcite Precipitation, Ahsan Ali

Doctoral Dissertations and Master's Theses

Climate change is causing wildfires to occur more frequently and with higher intensity. Leading to wide range of impacts on agriculture, infrastructure, and the environment. Wildfires affect soils by burning their organic matter, resulting in an immediate deplete of nutrients and a significant reduction in nitrogen level. Wildfires also alter soils’ physical properties and make them less resistant to erosion which results in debris flows when wildfire are followed by a rainfall event. The reduced activity of microorganisms that aid in nutrient absorption makes the soil less effective in supporting plant life. Microbial Induced Calcite Precipitation (MICP) was found to …

Rfid Security For Iot Airport Infrastructure, Owen Guerra-Mondragon Saenz, Aaron Tulino, Benjamin Higgins, Philippe Shchetinin, Sawyer Hansen

Discovery Day - Prescott

Radio Frequency Identification (RFID) is a technology that uses active and passive tags to communicate via radio signals at various frequencies. Currently, it is being used in several applications in areas like merchandise tracking during transit, inventory management, access control for authorized personnel, and data sharing via Near Field Communication (NFC). RFID technology is used in airports to track both people (passengers and employees) and luggage. For employees, RFID helps control access to specific areas based on their role or hierarchy within the organization, allowing them to enter restricted zones based on their permissions. For passengers, RFID plays a crucial …

Comparative Performance Analysis Of Cryptographic Workloads Across Cloud Providers: A Multi-Language Study On Faas And Iaas Platforms Dataset, Jeremiah Webb

Doctoral Dissertations and Master's Theses

Cloud computing has become a relatively new paradigm for the delivery of compute resources, with key management services (KMS) playing a crucial role in securely handling cryptographic operations in the cloud. This paper presents the microbenchmark of cloud cryptographic workloads, including SHA HMAC generation, AES encryption/decryption, ECC signature/verification, and RSA encryption/decryption, across Function-as-a-Service (FaaS) and Infrastructure-as-a-Service (IaaS) in conjunction with KMS offerings from Ama- zon Web Services (AWS) and Microsoft Azure to conduct a comparative performance analysis. The methodology involves the AWS Cloud Development Kit (CDK) and the Bicep language to deploy AWS Lambda Functions and Azure Functions, respectively, to …

Adaptive Control Of Thrusters To Account For Deficiencies In Actuator Effectiveness And Model Uncertainties, Matthew Stanko

Doctoral Dissertations and Master's Theses

Future space missions are expected to become ever more ambitious and challenging. A successful mission requires advanced and resilient control algorithms that enable missions, such as satellite refueling, on-orbit inspection, and end-of-life servicing. This thesis explores the development and application of robust and adaptive control laws for an over-actuated spacecraft system with 3 degrees of freedom (DoF) to mitigate the effects of actuator deficiencies and system uncertainties. Additionally, the nature of the system being over-actuated allows for particular actuator degradation and failure. For stability and command tracking, a novel controller is designed and augmented with sliding mode control, adaptive control, …

Analysis Of Responder-Involved Struck-By Crashes, Jacob Wilhelm

Doctoral Dissertations and Master's Theses

Emergency responders face significant risks of injury and death from struck-by crashes while operating on or near roadways. Annually, about 50 responders are killed, and hundreds more are injured, leading to operational disruptions and damage to life-saving equipment (ERSI, 2024). This study takes a data-driven approach to identify key risk factors and effective countermeasures for reducing the severity of struck-by crashes. Key findings indicate that struck-by crashes most frequently occur on weekends during late-night hours (2 AM–4 AM), often at crash scenes or disabled vehicle scenes on limited-access highways. Driver behavior – particularly “D” drivers (distracted, drugged, drowsy, disgruntled) – …

Evaluating The Impact Of Access Density On Pedestrian And Bicycle Safety, Charles Hruda

Doctoral Dissertations and Master's Theses

This study examines the impact of access density on pedestrian and bicycle crash rates in urban areas of Florida. Access management, defined as the strategic control of vehicular access points along roadways, plays a crucial role in mitigating conflicts between various roadway users. Previous research has established a positive correlation between access density and crash rates, yet limited studies have analyzed its effects on vulnerable road users such as pedestrians and cyclists.

To quantify these impacts, this study identified high-crash roadway segments using Florida Department of Transportation (FDOT) data. Geometric, traffic, crash, and access management information was collected and analyzed …

Engineering Anisotropic Porosity In Green Parts From Binder Jet 3d Printing, Reshma Chandrashekhar Kubsad

Doctoral Dissertations and Master's Theses

Binder Jet Additive Manufacturing (BJAM) is a promising metal additive manufacturing technique that enables the fabrication of complex geometries without the need for support structures. However, the inherent porosity in green parts, remains a challenge in achieving desired mechanical properties and performance. Instead of treating porosity as a limitation, this thesis explores engineering of anisotropic porosity engineering, where controlled variations in porosity in the green parts can be used to enhance functionality and efficiency in specific applications. The objective of this research is to investigate and analyze the key print parameters that influence green part density. By systematically varying layer …

The Interaction Of A Transient Forward Axial Disturbance Flow With A Rotor, Zhuorui Li

Doctoral Dissertations and Master's Theses

This research presents an in-depth investigation of the aeroacoustic characteristics of a scaled-down Joby Aviation rotor, focusing on its performance under realistic conditions for urban air mobility (UAM). Utilizing a high-fidelity numerical simulation approach that combines Large-Eddy Simulation (LES) and Unsteady Reynolds-Averaged Navier-Stokes (URANS) models, the study effectively captures the complex aerodynamic and acoustic interactions inherent in rotor operations. Validation of the numerical framework was achieved through comprehensive comparisons with available experimental data, demonstrating a high level of accuracy in predicting both aerodynamic performance metrics, including thrust and torque, as well as acoustic emissions. The simulation revealed significant impacts resulting …

Antenna Multi-Band Enhancement By Employing Negative Impedance Converters, Kevin Pepin

Doctoral Dissertations and Master's Theses

This thesis presents the implementation of a Negative Impedance Converter (NIC) integrated with a planar monopole antenna, originally centered at 2.9 GHz, to create a multi-band network. The network exhibits resonances at frequencies of 0.9 GHz, 1.5 GHz and 1.9 GHz. The work highlights the design process of pairing a NIC with a capacitive, single-band antenna, addressing key challenges such as overcoming the limitations associated with low self-resonant frequency (SRF) inductors. The design process included the use of measurement-based component models and radio-frequency simulations using Keysight Advanced Design Systems (ADS). The developed NIC emulates a -0.99 pF capacitor using two …

Aeroacoustics Applications To Jets And Rotors, Michael Marques G.

Doctoral Dissertations and Master's Theses

Aeroacoustics plays a critical role in the advancement of propulsion technologies for both conventional and emerging aerial systems. This dissertation investigates two key topics: noise suppression in supersonic rectangular jets and rotor noise characterization in hover and ground effect. Using high-fidelity numerical simulations and theoretical analyses, this research aims to develop effective noise mitigation strategies and improve predictive methodologies.

The first part of this study focuses on the reduction of noise in supersonic rectangular jets through active control techniques. A novel approach utilizing unsteady microjet actuation at the nozzle lip is explored to disrupt the formation of large-scale turbulent structures …

Coupled Dynamics In The Cislunar Region And Spacecraft Attitude Prediction In A Higher-Fidelity Model​, Annika Anderson

Doctoral Dissertations and Master's Theses

The cislunar region of space is a complex, multi-body dynamical environment that cannot be modeled trivially. Traditional point-mass assumptions made to simplify the mission design process may be insufficient for accurately predicting spacecraft motion in environments where orbit-attitude coupling is non-negligible. One of the most famous of such models is the circular restricted three-body problem. This thesis advances the state of the art in astrodynamics by modeling all bodies in the problem as rigid bodies, allowing for spacecraft orientation to be propagated and considered. Two models are under consideration—the circular restricted full three-body problem (CRF3BP) and a full higher-fidelity ephemeris …

Machine Learning Methods For Hypervelocity Fragment Flyout Characterization, Katharine Larsen

Doctoral Dissertations and Master's Theses

Resulting from breakup events, such as collisions and explosions, hypervelocity fragments create potential hazards for both terrestrial and on-orbit environments, such as terrestrial weapons explosions and satellite breakup events, respectively. To avoid unnecessary damage, an accurate understanding or characterization of hypervelocity fragmentation events is vital. Currently, publicly available two-line elements collected from on-orbit breakup events are limited, excluding pre-detonation parent body conditions, such as orientation, and information of smaller fragments. The uncertainty of these datasets varies between each collected set. Therefore, the overall goal of this work is to employ machine learning to estimate distribution characteristics of a space debris …

Automated Plant Morphological Assessment And Microbial Community Monitoring In Simulated Lunar Regolith, Collin R. Topolski

Doctoral Dissertations and Master's Theses

Upcoming lunar bases will need to leverage in-situ resources to ensure long-term sustainability and reduce mission costs. One key challenge is food production, which could be addressed by growing crops in lunar regolith-based substrates. However, lunar regolith lacks essential nutrients, requiring organic amendments to support continuous plant cultivation. This study examined the impact of manure-amended lunar regolith simulant on Mizuna mustard growth while assessing microbial community diversity and functionality. To support this effort, a custom software pipeline utilizing an open-source library, PlantCV, was developed to automatically track plant leaf area and height via image analysis. Results indicated that amended rhizosphere …

Stability Limits Of Uncertain Systems In The Presence Of Unmatched Coupled Dynamics And Actuator Dynamics With Adaptive Architectures, Bronson Saulo

Doctoral Dissertations and Master's Theses

Uncertain systems with coupled dynamics and actuator dynamics are prevalent in various applications spanning private, commercial, and government sectors. While stabilization and command tracking strategies exist, they often rely on idealized assumptions, such as negligible actuator bandwidth limitations and matched coupled dynamics. In order to mitigate actuator-induced limitations, we first employ standard model reference adaptive control (MRAC) architectures. We then proposed two architectures: modified hedging reference modeled based MRAC and modified expanded reference model based MRAC. In order to deal with coupled dynamics, we used an observer design to estimate the states of unmatched coupled dynamics. In addition, Lyapunov stability …

Experimental Investigation Of Heat Transfer To Tightly Packed Cylinder Arrays, Cameron M. Sexsmith

Doctoral Dissertations and Master's Theses

With the increased emphasis on the development of hybrid electric aircraft and other electric driven vehicles, the thermal demand on batteries is increasing. Unique to the aviation sector is the combined need of high battery thermal loads and a light-weight thermal management system. A proposed configuration is an array of batteries directly cooled with a dielectric coolant. The knowledge of heat transfer characteristics of battery cooling is becoming an ever pressing issue due to the need to optimize volume and mass in a safe manner. Tighter spacings between batteries provide higher pack densities, however, at the cost of increased cooling …

Dual Quaternions For Gravity Recovery Missions, Ryan Kinzie

Doctoral Dissertations and Master's Theses

A dual quaternion-based modeling, state estimation and control approach is introduced as a better alternative to the traditional methods which are currently utilized for gravity recovery missions. The proposed modeling and control approach was verified against and compared to the tangent bundle to Special Euclidean Group 3 through MATLAB simulations. The dual quaternion-based approach shows superior performance over traditional linearized and uncoupled methodologies, in both modeling accuracy of spacecraft translational position, and the ability to control the pose of a test mass relative to its host spacecraft. Utilizing data products from the Gravity Recovery and Climate Experiment Follow-On mission, a …

Exploring A Novel Adaptive Mesh Refinement Strategy For High-Speed Cfd, Arjun Jaishankar Vedam

Doctoral Dissertations and Master's Theses

Adaptive Mesh Refinement (AMR) techniques to efficiently and robustly achieve grid independent solutions on multi-element unstructured grids is a topic of practical interest within the CFD community.

The current effort focuses on the efficiency of a novel Adaptive Mesh Refinement (AMR) strategy that is developed and evaluated for transonic high-speed flows using Ansys Fluent. The algorithm for marking cells for adaptation is designed to systematically reduce local truncation errors based on the curvature of the primitive vector field. The algorithm for marking cells for adaptation is described in sufficient detail to be portable to other flow solvers that offer AMR. …

Modeling The Dynamics Of Flexible Aerospace Vehicles Using The Theory Of Functional Connections, Carlo Lombardi

Doctoral Dissertations and Master's Theses

Modeling and control of flexible vehicles is a topic of high interest in the aerospace field and a key challenge lies in finding accurate mathematical representations of the flexible dynamics of continuous elastic structures that allow simple integration into estimation and control algorithms. The answer was found in approximating the dynamics of these systems with sets of coupled Ordinary Differential Equations (ODE) for which a well-established estimation and control theory is available. Each of the techniques employed to achieve this goal is characterized by its own strengths and limitations. Hence, the main objective of this research is to develop the …

On The Provenance Of Software Systems: Automating Software Traceability With Knowledge Graph And Large Language Model Synergy, Tyler Procko

Doctoral Dissertations and Master's Theses

The present dissertation delineates a system that enables those engaged in software development to automatically generate and maintain project life cycle provenance. All projects are implemented and made manifest with the development of artifacts, e.g., papers, code files, etc. Tools exist to accelerate artifact creation, but little focus is paid to the processes that produce them. In terms of Ontology, or, from Ancient Greek, the study of being, the two most basic entities in reality are Continuant and Occurrent, or, roughly, “Artifact” and “Process”. This dissertation posits that for any created artifact, its process of creation, i.e., its life …