Aerospace Engineering Commons^™

Evaluating Regularized Logistic Regression And K-Nn On Mnist Under Increasing Random Missingness, Daniel Markwei

Data Science and Data Mining

This paper investigates the effect of random missingness on the performance of regularized multinomial logistic regression and the k-nearest neighbors (k-NN) classifier for handwritten digit recognition on the MNIST dataset. In particular, we study L1-regularized (LASSO) logistic regression and L2-regularized (Ridge) logistic regression alongside k-NN. Varying percentages of random missingness were introduced into the original dataset, and each model was evaluated in terms of its classification performance. The results show that random missingness degrades the performance of all three classifiers. Overall, k-NN consistently achieves higher accuracy than both L1- and L2-regularized logistic regression across all missingness levels; however, its performance …

Constrained Dynamics Of Rapid Orbit Motion Emulator (Rome) Using Udwadia-Kalaba Approach, Keanu Brayman

Honors Undergraduate Theses

The Rapid Orbit Motion Emulator (ROME) is designed to be a hardware-in-the-loop (HIL) testbed for orbital control algorithms. It consists of a four-wheeled ground vehicle and a six-degree-of-freedom robotic manipulator. This work investigates the use of optimal control to execute orbital trajectories on ROME using the Udwadia-Kalaba (UK) formulation to model the system dynamics. The UK formulation is a novel method to derive equations of motion for constrained systems. Unlike traditional approaches, the UK approach can be applied directly to any constrained dynamical system. This project utilizes the UK approach to derive dynamics with trajectory following constraints for the ROME …

Aeroelastic Simulation Of Shape Adaptive Wing, Allan Alfred Kozich Iii

Honors Undergraduate Theses

Morphing wings provide aerodynamic qualities that normal fixed wings cannot, such as the ability to improve endurance yet maintain maneuverability, overcome strong gusts, vibrations, and shocks, and handle both ideal flight for both high and low speeds. A critical application of the new generation of morphing wings is the ability to overcome and affect the onset flutter, a self-excited oscillatory instability that has led to the destruction of aircrafts. This work investigates aeroelastic behavior and measurement of a meta-material structured "smart" wing and its attempt to delay the effect of flutter. The variable wing tip model is analyzed through finite …

Vibration-Based Control Of Nonlinear Dynamic Systems, Ossyris N. Bury

Honors Undergraduate Theses

This thesis investigates vibration-based stability as a mechanism for achieving self-stabilizing nonlinear dynamic motion in engineered systems. Inspired by biological hovering flight, in which periodic wing motion can passively enhance stability, the study explores how controlled oscillations can be used to stabilize otherwise unstable mechanical configurations. The research centers on a simplified dynamic model based on the Kapitza pendulum, an inverted pendulum with a vertically oscillating base, which serves as a foundation for understanding vibration-induced stabilization. Analytical modeling using Lagrangian mechanics is employed to derive the governing equations of motion and identify the excitation conditions required for stable inverted behavior. …

Investigation Of The Impact Of The Shape Of The Wings On Formula E Racing Car Performance: Enhancements For Optimal Aerodynamics, Ednie Marthe Adlaikah Jozil

Honors Undergraduate Theses

The aerodynamic performance of a Formula E chassis significantly dictates its overall race efficiency, directly impacting crucial parameters such as battery range and thermal management. This thesis investigates the external aerodynamics of the baseline Gen 2 Formula E car and evaluates the performance gains of two novel aerodynamic packages: a "Fully Modified" configuration and a "Flat Rear Wing" design. Computational Fluid Dynamics (CFD) simulations were conducted to analyze drag coefficients (Cd), downforce generation, and vehicle wake structures at race-relevant free-stream velocities (e.g., 37 m/s and 89 m/s). To ensure numerical robustness, the computational setup was validated using a smooth sphere …

Integrated Design And Trade Study Of A Sub-Ambient Ammonia Fuel Storage And Delivery System For Narrow-Body Commercial Aircraft, Ethan Taylor

Graduate Studies Theses and Dissertations 2026

This study develops an integrated design framework for a sub-ambient anhydrous-ammonia fuel storage and delivery system for narrow-body commercial aircraft, using the Boeing 737 MAX 8 as the baseline platform. Ammonia was selected because it contains no carbon in its molecular structure, benefits from an established global production and distribution infrastructure, and offers more practical storage conditions than several alternative carbon-free energy carriers. However, its relatively low energy density, toxicity, material-compatibility requirements, and combustion hazards require substantial modifications to power conventional commercial aircraft fuel storage and delivery systems.

The study proposes an integrated design and initial analysis of a sub-ambient …

Characterization And Experimental Study Of Ammonia-Hydrogen Flames Inside A Toroidal Jet-Stirred Reactor At Atmospheric Conditions, Oli Marquez Valenzuela

Graduate Studies Theses and Dissertations 2026

Due to rising concerns about global surface temperatures and carbon emissions, there has been an increased interest in studying alternative fuels. Ammonia and hydrogen are fuels with the potential to replace general biofuels, hydrocarbons, and sustainable aviation fuels, as they do not contain any carbon, eliminating carbon emissions. However, they are both difficult to work with. Hydrogen has great combustion characteristics such as low ignition energy, high flame speed and lower heating value. However, it is volatile and difficult to store, requiring it to be compressed to high pressure or cooled to incredibly low temperatures. Ammonia can be used as …

Structural Batteries For Aerospace Applications, Tariqullah Wardak

Honors Undergraduate Theses

There is increasing pressure on the aviation sector to lower carbon emissions and switch to entirely electric and hybrid propulsion systems. However, the feasibility of standard lithium-ion batteries for long-range aircraft is limited, as they add substantial weight and occupy significant volume. Structural batteries, which combine load-bearing capability with energy storage, offer a potential pathway to lighter and more efficient aerospace systems.

This work investigates a carbon-fiber-based structural battery that utilizes carbon fiber as both a current-collecting, load-bearing electrode and a component of the composite structure. In contrast to lithium-ion chemistries, a zinc-based aqueous electrolyte is chosen for better environmental …

Cfd Analysis Of A Full Heat Exchanger Between Ammonia And Supercritical Co2 In Aviation Application, Mairah Ahmed

Graduate Studies Theses and Dissertations 2026

The aviation industry’s transition toward lower-carbon propulsion systems has accelerated interest in alternative fuels, including ammonia–hydrogen fuel blends. In this work, a supercritical CO2 Brayton cycle is integrated with the exhaust stream of a turbofan engine to recover waste heat and utilize it for ammonia preheating and cracking. The recovered thermal energy raises the ammonia temperature to the level required for catalytic decomposition, enabling onboard hydrogen production. The proposed architecture combines ammonia cracking with a high-bypass, two-shaft turbofan engine representative of the propulsion system employed on the Boeing 737 MAX 8. This approach addresses the challenges associated with onboard hydrogen …

Machine Learning Modeling Of In-Situ Effective Thermal Conductivities And Ablation Behaviors Of Ceramic Matrix Composites Under Hydrogen Combustion Environments For Gas Turbine Engines, Jayanta Bhusan Deb

Graduate Studies Theses and Dissertations 2026

Through the integration of experimental characterization, machine learning, deep learning, numerical modeling, and physics-informed artificial intelligence, this dissertation explores the thermal performance of polymer-derived ceramic matrix composites (CMCs) for hydrogen combustion environments. The polymer infiltration and pyrolysis (PIP) process was used to create Yttria-stabilized zirconia (YSZ)-fiber-reinforced ceramic matrix composites, which were then experimentally assessed under hydrogen torch and hydrogen combustion conditions typical of next-generation gas turbine and aerospace propulsion systems. Front- and back-surface temperature measurements were used to continually monitor thermal reactions, and post-test microstructural characterization and numerical simulations were carried out to evaluate material integrity and heat-transfer behavior. To …

Flow Field Characterization Of The Hyperreact Vitiated Hypersonic Wind Tunnel, Erik R. Fernandez

Graduate Studies Theses and Dissertations 2026

Reliable interpretation of hypersonic ground-test data requires knowledge of the thermochemical state delivered to the test section, especially in combustion-heated facilities where the gas is chemically altered before nozzle expansion. This thesis investigates the HyperReact vitiated hypersonic wind tunnel using the effective specific-heat ratio, γeff, as an experimentally inferred indicator of the coupled chemical and gas-dynamic behavior of hydrogen-air vitiated flow. HyperReact produces high stagnation temperatures through hydrogen-air combustion before expanding the mixture through interchangeable converging-diverging nozzles. During this expansion, temperature-dependent specific heats, molecular-weight changes, finite-rate chemistry, and internal energy relaxation can modify the relationship between Mach number, pressure ratio, …

Investigation On Selective Catalytic Reduction For Retrofit Of Commercial Aviation Aircraft Engines, Connor M. Wall

Graduate Studies Theses and Dissertations 2026

As the aviation industry continues to grow, the ever-increase of emissions from the sector becomes a growing concern. While the International Civil Aviation Organization (ICAO) set a goal of net-zero carbon emissions by 2050, there are other emissions like contrails and NOx that must still be addressed. Selective Catalytic Reduction (SCR) has been used in the transportation and power generation industry for over two decades and has been an effective solution for NOx reduction. Even with the success SCR has had in other industries, its capabilities in the aviation industry have been trivially investigated. Aircraft engines pose an unique challenge …

Computational Regolith Mechanics And Instrumentation Development For Lunar Exploration And Resource Utilization, Jared M. Long-Fox

Graduate Studies Theses and Dissertations 2026

Sustained exploration of the Moon requires quantitative understanding of lunar regolith properties to support scientific investigation, in situ resource utilization, excavation, and infrastructure development. This dissertation examines the mechanical interaction between robotic excavation systems and lunar regolith, emphasizing how regolith behavior both enables and constrains exploration-focused and exploration-enabled science. Computational excavation models were compared to laboratory data to evaluate prediction of excavation forces and to develop metrics of excavation efficiency. Laboratory experiments using high-fidelity lunar regolith simulants were conducted to characterize pressure-sinkage behavior, shear strength, and angle of repose across a range of material states. Common analytical excavation and terramechanics …

Chemical Kinetic Experiments Of Monomethyl Hydrazine Combustion Products At High Pressures And High Temperatures In A Shock Tube, Cooper Q. Mills

Graduate Studies Theses and Dissertations 2026

This study presents experimental shock tube laser absorption spectroscopy data to validate high-pressure and high-temperature chemical kinetic mechanisms for mixtures of H₂/air, NH₃/air, and H₂/CO/NO₂/air diluted in argon (95-98%) at high pressures (5, 10, 25 bar) and high temperatures (1000 to 2150 K). The mixtures were at equivalence ratios of 0.5, 1.0, and 1.5 to cover the range of possible conditions experienced throughout practical combustors. Laser absorption spectroscopy data was measured for NH₃, H₂O, CO, and NO using a novel multi-species setup. Chemical kinetic mechanisms contain the fundamental …

Thermomechanical Modeling Of Transpiration Surfaces For Hypersonic Propulsion, Spencer D. Smith

Graduate Studies Theses and Dissertations 2026

Hypersonic flight vehicles are a promising form of high speed passenger transport and efficient space access architectures. However, they are fundamentally a thermally limited technology. High heat fluxes exceeding 10 MW/m2 and gas temperatures between 3000-4000K can be found both within the engine, and on the outer surface. Current conventional engineering materials are non-viable at these conditions. In order to make these materials viable, active cooling strategies could be utilized. One particularly promising type is transpiration cooling, where a coolant is diffused through a porous surface. Although researched heavily in the 1960s, adoption is still minimal. Part of the reason …

High Intensity Ablation By Laser Filaments At Standoff Distances, Owen Thome

Graduate Studies Theses and Dissertations 2026

The high-power densities delivered to a target material by a laser allow for melting and vaporization to occur, a process called laser ablation. At higher intensities, plasma formation occurs and more complex material removal mechanisms take place. As laser power increases, nonlinear effects occur during propagation. One such effect, Kerr self-focusing, leads to beam collapse and ionization, resulting in a channel of plasma and region of high intensity light referred to as a laser filament. Filaments carry intensities on the order of 10¹³ W/cm² to significant distances without the use of large-scale focusing optics. Laser filament ablation is …

Effects Of Back-Pressure On Pseudo-Shock Systems, Emil C. Alunno

Graduate Studies Theses and Dissertations 2026

The isolator of a scramjet engine houses a pseudo-shock, a compressive flow structure that raises the static pressure and decelerates the incoming supersonic flow for efficient combustion while shielding the inlet from the elevated pressure downstream. Under sufficient back pressure the leading shock bifurcates and forms a shock train followed by a shockless mixing region, and the resulting system oscillates even under nominally steady conditions; this unsteadiness distorts the flow, can drive the pseudo-shock out of the isolator and unstart the inlet. This thesis experimentally examines how a pseudo-shock in a constant-area isolator at a measured entrance Mach number of …

Numerical Investigation Of Reacting Flow In Pmma-Fueled Solid Fuel Scramjet Combustors Under Experimental Test Conditions, Hunter Bassett

Graduate Studies Theses and Dissertations 2026

A simplified steady RANS-based numerical study of reacting flow in solid-fuel scramjet combustors is presented to evaluate the ability of commercial CFD frameworks to reproduce key features observed in experimental test sections. The work focuses on solid PMMA fuel in two supersonic combustor configurations: a cavity-assisted flameholding combustor and a variable-angle diverging combustor. The cavity combustor is analyzed as a baseline case and results are compared directly with experimental data. Three combustor geometry states corresponding to ignition, early-burning, and steady-burning conditions are investigated. Meshes are assessed through a systematic grid refinement method to establish grid independence. A novel variable-angle diverging …

Experimental And Computational Characterization Of A Rotorcraft-Tiltrotor Model Using Morphing Wings For Whirl Flutter Instability, Darrell Nieves Lugo

Graduate Studies Theses and Dissertations 2026

Tiltrotor rotorcraft configurations combine the capabilities of vertical and forward flight, offering a crucial and advantageous design for maximizing the operational flight envelope. This versatility enables broad adaptability across numerous designs and platforms, including unmanned aerial vehicles (UAVs), micro-air vehicles (MAVs), and vertical take-off and landing (VTOLs) aircraft. However, propeller-based aircraft are susceptible to an aeroelastic instability at high flight speeds known as whirl flutter. This instability phenomena is a crucial research task and problem to investigate, as with advances in manufacturing and vehicle designs, these can yield new rotorcraft formats capable of advancing the flight envelopes at higher cruise …

On Performance And Applications Of A Liquid Fueled Pulsed Flame Jet Igniter, Gerardo A. Rodriguez

Graduate Studies Theses and Dissertations 2026

As global demands for supersonic and hypersonic flight heighten, high-speed air breathing propulsion technologies stand out as a worthwhile direction to overcome many of the limitations that turbomachinery-based engines face at supersonic speeds. Air breathing propulsion concepts are attractive for their geometrical simplicity, using supersonic incoming air to provide compression. Scramjet flight vehicles operate within the hypersonic flight regime and have been a global research topic, especially in the 21st century, for defense and combined cycle engine architectures. As scramjet technology continues maturing towards widespread use, efforts have converged on liquid hydrocarbon fuels for storage, range, and operational benefits. Flight …

Experimental Characterization Of Obstacle-Driven Ddt And The Performance Of Relief Dump Tanks In Detonation Systems, Bryan Suarez

Graduate Studies Theses and Dissertations 2026

This study investigates the lifecycle of a detonation event in a modular detonation
tube facility. It focuses on the mechanisms of deflagration-to-detonation transition
(DDT) and the effectiveness of a pressure relief system. With a stoichiometric
hydrogen-oxygen mixture, the research aims to characterize the effect of
interchangeable turbulator obstacles on the DDT process. By varying blockage
ratios and obstacle geometries in the pre-detonation section. This study identifies
how physical characteristics influence transition efficiency. The experimental data
collected includes pressure spikes and wave speed which were then used to
validate against the Chapman-Jouguet (CJ) theory at initial pressures of 350 Torr
and …

A Framework For Optimizing Creep Model Parameters From Conventional And Accelerated Creep Tests, William D. Day

Graduate Studies Theses and Dissertations 2026

The demand for efficiency in power generation and propulsion requires higher firing temperatures and reduced cooling air consumption which raises metal temperatures. This makes simplistic creep evaluations, such as Larson-Miller and Orr-Sherby-Dorn parameters, inadequate. Finite element analysis (FEA) must simulate primary and secondary creep, predict failure, and provide design guidance. Gas turbine components, expected to last over 100,000 hours, often require extrapolation of limited test data for new materials. It is essential that robust creep simulations be developed efficiently, accurately, and effectively use limited test data.

This dissertation describes an optimized framework for efficient creep testing and rapid construction of …

Cylinder Wake Stability Effects Of Passive Forebody Modification And Active Harmonic Actuation, Matt Duran

Graduate Studies Theses and Dissertations 2026

This dissertation investigates the manipulation of global and three-dimensional instabilities in the wake of a circular cylinder through two separate flow control methods. This study first focuses on the influence of attached leading edge forebodies as a form of passive flow control designed to introduce upstream streamline curvature, where the curvature takes the form of a concave and convex case. We demonstrate that for both cases this induced curvature significantly modifies the primary instability, which suppresses periodic vortex shedding (Von Kármán vortex street). We found an increase in critical Reynolds number of 56.6 and 60.1 for the concave and convex …

Effects Of Hydrogen Enrichment And Premixing On Flame Stability In A High-Pressure Axial-Stage Combustor, Alexandre Fernandes C. Santiago Filho

Honors Undergraduate Theses

The addition of hydrogen to conventional fuels enhances reactivity and can increase the risk of flashback in premixed gas turbine combustors. This study investigates the effects of premixing length and hydrogen concentration on flame stability in a high-pressure axial-stage combustor. Experiments were conducted at the UCF Propulsion and Energy Research Laboratory using a two-stage configuration, where the primary stage provided a high-temperature vitiated crossflow using a hydrogen-piloted, premixed methane–air mixture, and hydrogen-enriched methane–air mixtures were injected through a concentric fuel-tube injector in the axial stage. Premixing length was varied for pure hydrogen flames, and hydrogen concentration was varied at a …

Turbine Exhaust Cylinder And Manifold Wake Interactions At High Swirl Angle, Christian A. Anzalotta

Graduate Studies Theses and Dissertations 2026

A commonly observed flow interaction in industrial gas turbine (IGT) exhaust diffuser configurations is investigated, where upstream structural wakes interact with downstream airfoil-like components, potentially leading to unsteady loading. To better understand the mechanisms contributing to this behavior, a scale-model is designed. Dynamic similarity is achieved by matching the Strouhal number (St) of the vortex shedding from the strut. A bell-mouth followed by a swirler is installed in front of the strut to mimic the flow angles at the inlet section of the turbine exhaust. Experiments are conducted for three swirl angles, namely, 30°, 45°, and 60°. Power spectra computed …

Damping Modulation Of Dampened Kapton Surfaces, Sebastian Esteban

Honors Undergraduate Theses

When droplets are vibrated or disturbed, they can exhibit a complex sloshing motion, an understudied behavior in drop physics. Droplet sloshing involves a complex combination of transverse and longitudinal motion that changes the droplet's effective weight on the surface the droplet is on. Our current understanding stems from preliminary work focusing on a cantilever beam of fixed thickness and variable viscosity of the liquid being sloshed. This investigation will focus on how variable cantilever thickness and constant viscosity for a liquid being sloshed affects the beam's deflection under consistent vibration. It will also investigate how the natural frequency of a …

Effects Of Changes In Strouhal And Reynolds Numbers On Beetle Wing Aerodynamics, Keith L. Thiha

Honors Undergraduate Theses

Insect flight has long been a subject of interest across the scientific community, largely due to the exceptional aerodynamic performance insects demonstrate relative to their size. Insects tend to have very high aerodynamic performance characteristics like thrust and lift generation compared to their size. This has many potential applications in improving aircraft performance, however the flow phenomena concerning insect wing aerodynamics is still an area of ongoing research. This study aims to investigate how variations in key nondimensional flow parameters—specifically the Reynolds number and Strouhal number—affect the aerodynamic performance of beetle wings. Strouhal numbers ranging from 0.2 to 0.6 were …

The Aerodynamics Of Bird Perching: Understanding Wing And Body Interactions In Pigeon Flight, Anirudh Sriram

Honors Undergraduate Theses

During landing, birds often execute a perching maneuver. The perching maneuver refers to the complex series of actions that birds, and pigeons in particular, will perform when landing. They will typically decelerate by pitching their body to a high angle of attack and spreading their wings. It is believed to help achieve better control and reach optimal lift and drag coefficients. This study seeks to better understand the vortex interactions between the main and tail wings during this maneuver. However, it is still an unexplored phenomenon. Thus, two bird models were conceived to analyze it, one with and one without …

Utilizing Pneumatic Artificial Muscles To Simulate Wingbeat Kinematics For Morphing Uav Wings, Vireli S. Anbarasu

Honors Undergraduate Theses

The controlling muscles of a bird wing change stiffness and length to provide high efficiency when executing a flight maneuver. This variable stiffness allows the muscles to cycle between increasing energy, transmitting it, and restoring it, allowing an overall increase in mechanical and aerodynamic efficiency. Inspired by this, we have developed a system that uses pneumatic artificial muscles (PAMs) to actuate a morphing wing. The stiffness in the PAMS can be controlled to mimic the changes bird flight muscles undergo when executing a forward flapping maneuver. We will evaluate the performance of the PAMs in actuating a morphing wing through …

Methods Of Variability Reduction In Ramjet Fuel Injection Using Fluid-Structure Interactions, Egan J. Rigney

Honors Undergraduate Theses

The Liquid Jet in Crossflow (LJIC) method of fuel injection in ramjet engines is widely used and well-studied. However, they experience variation in their behavior at different altitudes and flight speeds due to the varied flow conditions following the inlet. This variation becomes more noticeable at high-temperature and high-speed airflow conditions. The optimized and consistent breakup of liquid fuel is a key component in ramjet engine design as there is a minimum surface area requirement of the droplets for combustion to occur. Local equivalence ratios also have a significant influence on the effectiveness of combustion. As such, researchers at the …