Aerospace Engineering Commons^™

Graph Based Planning With Guarantees, Trazon Tyrik Jimerson

Mechanical Engineering ETDs

This thesis presents two graph-based methods with formal guarantees for motion planning and routing. First, the invariant-set motion planner (ISMP), which uses constraint admissible positive invariant (CAPI) sets of closed-loop dynamics, is adapted for spacecraft attitude planning to avoid moving keep-out zones. Contributions include time bounds for maneuvers via exponential stability, a single-stage reachability graph from one-step backward reachable CAPI sets, and its multi-stage expansion to certify node safety over time. Simulations verify safe attitude control with moving obstacles. Second, we formulate a convex optimization problem over a network for evacuation planning with operational constraints such as helicopter capacity and …

Development And Validation Of A Machine-Learned Actuator Line Model For Rotors, Joshua L. Bowman

Theses and Dissertations

This dissertation develops and validates a machine‑learned (ML) actuator line model (ALM) as an advancement in rotor modeling that can be applied to diverse engineering applications. The model addresses two standard ALM limitations: dependence on pre‑tabulated lift and drag coefficients and the inability to represent unsteady inflow. The ML‑ALM is trained on a hydrokinetic blade‑resolved simulation database of blade‑element forces under unsteady conditions, and is queried at run time to supply axial, tangential, and spanwise forcing at each actuator element. Validation covers solitary rotor performance and wake predictions against experimental data, and verification in an inline configuration against blade‑resolved simulations …

Investigation Of The Flow Field Morphology Of Film Cooling In Supersonic Flow, Umberto Sandri, Massimiliano Ferro, Alessio Picchi, Antonio Andreini, Bruno Facchini, Marc D. Polanka

Faculty Publications

Film cooling is widely implemented in highly thermally stressed gas turbine components. Its performance has been extensively investigated for several decades and many results are available in the literature. In conventional gas turbines, regions of supersonic flow are not prevalent and should generally be avoided. For this reason, results relative to film cooling in supersonic flow are limited. Nevertheless, a new interest related to Rotating Detonation Combustors (RDC) and supersonic turbines is growing. The implementation of those engine components in a gas turbine is likely to need film cooling for thermal protection. In this context, it becomes crucial to gain …

Parameter Informed Reinforcement Learning For Vehicle System Identification, Nathan Schaff

Doctoral Dissertations and Master's Theses

Accurate system identification is essential for modeling and controlling vehicle dynamics. This dissertation explores the application of Parameter Informed Reinforcement Learning (PIRL) as a novel approach to system identification (SYSID). PIRL integrates prior system knowledge, such as physical parameters, into reinforcement learning (RL) frameworks to improve estimation accuracy. The study begins with an overview of traditional SYSID methods and then introduces PIRL as a modification of standard RL. The research applies PIRL to short-period aircraft dynamics, demonstrating its effectiveness in both offline and online learning frameworks. The dissertation then further explores PIRL’s utility in an indirect model reference adaptive control …

In-Situ Investigations Of Calcium-Magnesium-Aluminosilicates (Cmas) Infiltration Effects On Thermal Barrier Coatings Under Extreme Environments Replicating Jet Engines, Zachary Stein

Doctoral Dissertations and Master's Theses

Calcium-magnesium-aluminosilicate (CMAS) particulates, such as sand or volcanic ash, are ingested by gas turbine jet engines during operation. When operating within high abundance regions, these particulates negatively interact and degrade the high temperature thermal barrier coatings (TBC) protecting underlying superalloy turbine blades vital to engine operation. These CMAS particulates melt within the engine and infiltrate into the ceramic coatings. In electron-beam physical vapor deposited (EB-PVD) TBCs, the CMAS within the intercolumnar gaps stiffens the coatings and causes thermomechanical induced high stress concentrations, risking crack formation. While molten, the CMAS thermochemically alters and destabilizes the coating, also risking coating failure. Premature, …

Performance Of Adaptive Wingtips On A Tailless Supersonic Business Jet, Khushi Piparava

2025 Fall Honors Capstones Projects - Archive

The growing interest in supersonic business travel has renewed focus on efficient, low-drag configurations that can achieve high performance while maintaining stability and structural integrity. This research investigates the aerodynamic and structural implications of adaptive folding wingtips on a tailless supersonic business jet (SBJ) concept designed under the SkyBreaker senior design program. Using a conceptual aerodynamic model based on linearized supersonic theory, the Polhamus leading-edge suction analogy, and an empirical compression-lift correlation, the study evaluates how varying wingtip droop angles influence lift, drag, lift-to-drag ratio (L/D), and static stability. The analysis was performed parametrically in MATLAB, using geometry inputs derived …

Orbital Reliable Printed Circuit Boards, Thomas Maxwell Starnes, Keegan Blake Jordan, Ian Griffith, Grant Monroe Pesqueira, Vishal Navin Patel

Senior Design Project For Engineers

Deep Interstellar Solutions is proposing a device to produce custom, serviceable printed circuit boards (PCBs) in low Earth orbit. This technology uses blank PCBs that are laser-etched and prepared for electrical components, then stored in the module. This method of PCB production allows for rapid repairs or prototyping without the need for subsequent resupply missions. By implementing this technique, future missions will achieve greater autonomy, sustainability, and resource efficiency. The goal of this development is to pioneer the creation of custom circuitry for use in deep-space missions where resupply is neither cost-effective nor timely.

Tunable Phase-Change Metasurfaces Coupled With Mid-Infrared Molecular Vibrations, Haotian Tang, Liliana Stan, David A. Czaplewski, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Chiral optical meta surfaces have emerged as a promising platform in coupling with molecular vibrational fingerprints through the enhanced light-matter interaction under different circularly polarized light illumination. This work reports the mode coupling between the mid-infrared phonon vibrations of polymethyl methacrylate (PMMA) molecules, and the thermally tunable chiral meta surfaces based on the phase-change material Ge₂Sb₂Te₅ (GST-225). Phase-change chiral meta surfaces with high circular dichroism (CD) in absorption and tunable plasmonic resonance in the frequency range of 48-56 THz are demonstrated, which covers the phonon vibrational frequency of PMMA molecules at 52 THz. The mode splitting features are observed in …

Low Power Magnetically Shielded Krypton Hall Thruster Design, Grace Klang

Honors Theses

This project investigates the design and modeling of a low-power Hall-Effect Thruster optimized for krypton propellant, serving as a continuation of Western Michigan University’s Hall thruster development series. Krypton is selected as an alternative to xenon due to its significantly lower cost and increased availability, though its higher ionization energy and reduced atomic mass introduce performance, ionization, and efficiency challenges that must be addressed through careful design. The goal of this study is to design two 300-W class thrusters capable of achieving high efficiency and long operational life on krypton propellant while maintaining full compatibility with existing laboratory facilities and …

Validation Studies Of A Dynamic Hybrid Rans-Les Turbulence Modeling Strategy For Cfd Simulation Of Gas Turbine Component Film Cooling, Cole Simmonds

Graduate Theses and Dissertations

Computational prediction of the flow physics associated with gas turbine film cooling is important for ensuring effective heat transfer design. These flow fields are highly turbulent and anisotropic, making the accuracy and efficiency of the chosen turbulence model an important aspect of performing high quality computational fluid dynamics (CFD) based analysis. Current industry standard Reynolds-averaged Navier-Stokes (RANS) turbulence models such as RANS k-ω SST, while computationally efficient, are subject to relatively high levels of uncertainty in their ability to predict these turbulent flow fields. In contrast, high fidelity methods such as Large Eddy Simulation (LES) are computationally very expensive, while …

Reverse Design Of Solid Rocket Grain Geometry, Yechan Kang

Master's Theses

The reverse design of solid rocket motors remains a challenging process due to the nonlinear relationship between the grain geometry and the internal ballistics. The reverse design process involves obtaining an optimal grain geometry given a target performance curve set by mission requirements, which is the inverse problem of the forward design. The purpose of this study is to assess the validity and implementation of neural network and simulated annealing algorithms to perform the reverse design process. A modified phase field model of the eikonal equation is derived to simulate the evolution of combustion surfaces over time, enabling burn back …

Development And Test Of An Automatic Mass Balancing System For Cal Poly's Spacecraft Attitude Dynamics Simulator, Cameron B. Zorio

Master's Theses

The Cal Poly Spacecraft Attitude Dynamics Simulator (SADS) is an ongoing project to develop an air-bearing platform capable of recreating on-orbit rotational dynamics with near frictionless and torque-free rotations. However, any offset between the platform's center of rotation and its center of mass will introduce a torque due to gravity.

This thesis presents the design, implementation, and experimental evaluation of a low-cost, automatic mass balancing system for the SADS to address this challenge. A new modular sliding mass system was developed that overcomes issues faced in previous iterations of the SADS, providing real-time positional control of the masses and a …

Design And Assessment Of A Single-Blade Rotary Wing For Use In Vertical Takeoff And Landing (Vtol) Aircraft, William C. Mcmasters

Mechanical & Aerospace Engineering Theses & Dissertations

A single-bladed propeller was designed to determine its efficacy in increasing efficiency of quadplane aircraft in the cruise configuration while still providing sufficient vertical lift for the vertical takeoff portion of flight. Aerodynamic theory predicts higher efficiency for single-blade propellers, resulting in a lower power requirement. A counter-weighted single-blade was modeled after a 10x5 model aircraft propeller used in small unmanned vehicles with a steel counterweight to balance centrifugal forces. The propeller was tested in the ODU wind tunnel to determine performance at various Advance Ratios (J). The research suggests that single-blade propellers show comparable performance compared to two-bladed propellers …

Design, Optimization, And Initial Results Of An Automatic Impedance Matching Network For Nitrogen Inductively Coupled Plasma, Logan Anthony Alvesteffer

Masters Theses

The electric propulsion industry is witnessing a strategic interest toward the utilization of molecular propellants as alternatives to noble gases due to increasing cost constraints and logistical requirements. This transition is hindered by a fundamental deficiency in the understanding of molecular plasma and radio frequency physics, including the excitation, dissociation, and ionization cross-sections, which mandates a reliance on computationally inefficient, empirically modified atomic thruster designs. Furthermore, current state-of-the-art electric propulsion devices, such as gridded ion thrusters and Hall effect thrusters, utilize an electrode (cathode) for ionization and are thus susceptible to chemical poisoning and material erosion, which is prevalent while …

Tradespace Exploration For Multiple Collaborative Vehicles, Mrunal Deshmukh

All Theses

Modern military operations demand systems that adapt to uncertain, rapidly changing missions across diverse terrains. Traditional single-platform vehicle design is insufficient for such complexity. This research introduces a hierarchical tradespace exploration framework for designing and evaluating families of heterogeneous ground vehicles under a System-of-Systems (SoS) architecture. The framework treats vehicle design as a co-optimization problem, where a “parent” vehicle (e.g., a Squad Multipurpose Equipment Transport) coordinates specialized “child” vehicles for reconnaissance, amphibious tasks, terrain traversal, and stealth missions. Unlike conventional approaches that optimize vehicles individually, this study emphasizes collaborative performance, resource sharing, and adaptability at the family level. Central to …

Understanding Policy Transfer Under Decomposition And Coordination: Sequential Reinforcement Learning With Relaxation-Based Feasibility Control, Aannand Lal

All Theses

This thesis investigates how decomposition and coordination (D&C) choices influence exploration, learning, and transfer in reinforcement learning (RL) based design frameworks. A unified methodology is developed to evaluate generality under decomposition and to demonstrate sequential coordination on a representative physical task. The generality study holds the underlying physics constant while varying problem presentation - specifically scalarization weights, objective orientations, and feasibility handling. A train-evaluate matrix is constructed in which each trained policy is assessed across all alternative decompositions. Set-based diagnostics quantify generality through exact-match identity, Jaccard similarity of distinct feasible states, total feasible coverage, and Pareto-front quality. Results show that …

Short-Arc Angles-Only Initial Orbit Determination For Leo And Geo Objects Using A Genetic Algorithm, Joseph R. Piini

Master's Theses

An ever-growing interest in utilizing space for scientific, commercial, and defense applications has led to an exponential rise in orbital debris recent years. With this sharp increase in space objects comes a greatly increased risk of potential collisions, necessitating an increase in Space Situational Awareness. In order to best mitigate the risk of future collisions in an increasingly congested space environment, it is crucial to be able to accurately determine the orbits of these new objects for trajectory tracking. This process is initial orbit determination (IOD), and is especially difficult when only observation angles are available for short observation times. …

2025 Summer-Fall Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for summer and fall 2025. Includes photographs, upcoming events, recent publications, and student profiles.

When Textures Trim Drag: Micro-Structures For Adaptive Drag Reduction And Flow Authority, Miguel Angel Olvera

Theses and Dissertations

Turbulent boundary layers are a major source of drag and performance loss. This thesis investigates Triangular Porous Texturing (TPT), apex-forward microstructures with optional bleed channels, as a passive concept for simultaneously reducing skin friction and strengthening boundary layer momentum near separation. Low-speed wind tunnel tests are conducted over tripped turbulent boundary layers on flat plates with three surfaces: a smooth baseline, a solid-crest TPT array isolating the knife-edge “slip-cut” effect, and a porous-bleed TPT array whose paired micro-channels vent a small fraction of the free stream. Time-resolved PIV provides wall-normal velocity fields; skin friction is inferred from near-wall shear, and …

Efficient Adaptive Spline-Based Path Planning For In-Space Servicing, Assembly, And Manufacturing Applications, Christian Lozoya

Open Access Theses & Dissertations

Autonomous robotic systems operating in cluttered and partially observed environments require trajectory generation methods that produce smooth and dynamically feasible motion while reacting to locally sensed obstacles. This requirement is especially pronounced for free-flyer and in-space servicing, assembly, and manufacturing (ISAM) platforms, where onboard sensing is sparse, global environmental information is unavailable, and communication or computational resources are constrained. In such settings, motion plans must be updated online using incomplete and rapidly changing local observations, while avoiding excessive replanning that can lead to oscillatory or unstable behavior. Many existing approaches either rely on dense optimization over extended horizons, which is …