Propulsion and Power Commons^™

Spaceotter: A Floating Spacecraft Simulator Air Bearing Vehicle For Hardware-In-The-Loop Experiments And Research, Alexander Debartolo

Master's Theses

Growing interest in nanosatellites has increased demand for accessible ground-testing methods, which have historically been expensive and restricted. Floating Spacecraft Simulators (FSS), built around Air Bearing Vehicles (ABVs), address this gap by approximating a zero-gravity, friction-minimized environment suitable for testing spacecraft control systems, robotics, and propulsion on the ground.

This thesis presents the design, realization, and initial performance characterization of the Space Optically Tracked Testbed for Experiments and Research (SpaceOTTER) ABV, developed for the Cal Poly Space Robotics Lab. SpaceOTTER is the first step toward emulating the 3 degree of freedom (3-DOF) planar dynamics of a simulated spacecraft and is …

Design And Development Of A Resonance Ignition System Using Gaseous Propellants, Benjamin J. Hoefer

Master's Theses

This work presents the development and experimental evaluation of a resonance igniter (RI) operating with premixed gaseous propellants. Resonance ignition is a non-electrical ignition concept in which an underexpanded jet impinges on a closed-end Hartmann–Sprenger tube (HST), generating cyclic compression and expansion waves that rapidly heat gas near the tube endwall. A modular experimental system was designed and built to investigate resonance ignition using methane–air and methane–oxygen mixtures. The system includes a supplemental configuration that may probe for mixture conditions favorable to ignition, informing RI testing. Pressure and temperature measurements were used to characterize pressure control, mixture pressure ratio (MPR), …

Aerodynamic Design And Structural Evaluation Of A Global Minimum Torque Inspired Multirotor Propeller, Zeke Bukovansky

Master's Theses

This thesis develops a repeatable design, CAD, aerodynamic postprocessing, structural screening, and manufacturing feasibility workflow for a 22-inch global minimum torque inspired multirotor propeller. Matched MIL and GMT geometries were compared at a 35 N, 4000 rpm static-hover operating condition using BEMT/XFOIL aerodynamic postprocessing, with diameter, blade count, chord distribution, airfoil schedule, and target thrust held constant. The final modeled comparison predicted a modest 1.5% reduction in torque and shaft power for the GMT case while maintaining the same thrust target. CAD construction, MATLAB reduced-order beam model, Abaqus screening, and manufacturing planning were used to identify geometry level structural and …

Comprehensive Analysis Of Spray Development And Low Temperature Combustion Characteristics In A Cvcc With Nvh Of Renewable Aerospace Fuels: Hefa & Ft Synthetic Kerosene (S8) Compared To Jet-A & Ulsd, Coleman Norton

Honors College Theses

A comprehensive analysis was conducted to research the viability of Hydroprocessed Esters and Fatty Acids (HEFA) and S8 Synthetic Kerosene fuels as a drop-in replacement for conventional petroleum-based fuels, Jet-A and ULSD (Ultra Low Sulfur Diesel). Global transportation remains heavily dependent on liquid fossil fuels, while renewable aerospace fuels offer a promising pathway to reducing life cycle greenhouse gas emissions and pollution. However, the combustion performance and long-term feasibility of these fuels remain insufficiently characterized. This study performed a thorough assessment of each fuel's thermophysical and combustion properties. Thermophysical characterization encompassed viscosity, freezing point, energy density, spray atomization, and volatility. …

Stabilized Cargo Relay Aircraft For Precision Payload Yielding, Dato A. Tabidze, Michael Conely, Ben Courtney

Senior Design Project For Engineers

As military missions become more complicated, warfighters need more capable drones to use across diverse scenarios. The same also applies to civilian applications, like infrastructure inspection, package delivery, and disaster response. Current multirotor drones, also known as unmanned aircraft systems (UAS), provide simplicity, affordability, and ease of operation; however, their primary limitation is their low payload-to-weight ratio, which typically falls at 1:1 or less. The DARPA Lift Challenge aims to shatter the heavy lift bottleneck, seeking novel drone designs that can carry payloads more than four times their weight, which would revolutionize the way we use drones across all sectors. …

Range Extension Of Electric Propulsion General Aviation Aircraft Using Solar Technology, Mary Kathryn Shultz

Theses and Dissertations

Alternative propulsion technologies in aviation have been a long-time topic of interest as operators aim to bypass growing fuel prices and meet environmental sustainability requirements set globally. Research regarding alternative propulsion technologies is primarily centered around marginally improving efficiency of combustion systems or large-scale implementation of novel technologies. This research evaluates the feasibility of implementing solar-integrated propulsion for general aviation aircraft to extend range through a comparison of full-electric, hybrid solar, and internal combustion engine propulsion systems. This evaluation of existing technology by range analysis indicates that hybrid solar‑electric propulsion is viable primarily for short‑range training and recreational aircraft, rather …

Thermoacoustic Effects Of A Variable Equivalence Ratio In A Single Element Methane Combustor, Carter Green

Doctoral Dissertations and Master's Theses

Combustion instability is one of the leading factors in limiting the progress and innovations of liquid rocket engines and power plants. Under certain operating conditions, unsteady heat release and acoustic wave interactions can couple and lead to instabilities, such as self-sustaining pressure oscillations, that can lead to reduced combustor performance and potentially hardware damage. In this project, the thermoacoustic effects of controlling the equivalence ratio of a single-element natural gas combustor were modeled and analyzed. The project used Fidelity Pointwise for meshing, ANSYS Fluent for modeling, ERAU VEGA HPC for computing, and MATLAB for acoustic analysis. A numerical model of …

Numerical Investigation Of Rotor-Gust Acoustic Interactions Using The Overflow Cfd Solver, Jordan Mills

Doctoral Dissertations and Master's Theses

The rapid expansion of Urban Air Mobility (UAM) necessitates high-fidelity modeling to predict and mitigate the noise signatures of electric vertical take-off and landing (eVTOL) aircraft within dense urban landscapes. A critical unknown in community-noise certification is the aeroacoustic response of rotors to unsteady inflow conditions. This research addresses this gap by investigating the aerodynamic and acoustic behavior of a representative rotor subjected to time-harmonic inflow disturbances. By establishing a robust numerical framework, this thesis quantifies the relationship between periodic atmospheric gusts and their impact on rotor performance, unsteady blade loading, and subsequent sound radiation. The research consists of a …

Effect Of Nozzle Pressure Ratio On Thrust And Flow Behavior In A Supersonic De Laval Nozzle, Esha Jain

Doctoral Dissertations and Master's Theses

Supersonic nozzles operate across a range of flow regimes. While an ideally expanded condition yields optimal thrust, practical propulsion systems rarely operate at this design point due to variations in altitude and engine operating conditions. As a result, nozzles frequently operate in off-design conditions. In overexpanded regime, where the exit pressure is lower than the ambient pressure, shock-induced separation may occur within the divergent section of the nozzle, potentially degrading nozzle performance. Understanding the aerodynamic behavior of nozzles operating under off-design conditions is therefore important for improving propulsion system performance and stability. In particular, direct thrust measurements provide a key …

Dynamic Thrust Testbed For Uav Electric Motors, Colin M. Flowers, Robert C. Johnson Jr., Carson P. Holt

Williams Honors College, Honors Research Projects

This project seeks to bring new testing capability to the Zips Aero Design Team through the design, manufacture, integration, and testing of a dynamic thrust testbed for UAV electric motors. The project centers upon the revival and modification of a past prototype aircraft for use as a testbed for in-flight thrust measuring and recording. The team currently lacks the ability to test dynamic thrust under the operating conditions and flight speeds that are encountered in competition. Project technical areas include component and product design, electrical and electronics, and fluid mechanics, including the use of SolidWorks, MATLAB, and ArduPilot. Aside from …

Development And Integration Of A Liquid Rocket Propulsion System For A High-Power Rocket, Matthew A. Dipofi, Christina Griggy, Jonathan Armbrust, Jackson Frame

Williams Honors College, Honors Research Projects

The goal of this project is to integrate the Stinger liquid rocket engine, a regeneratively cooled LOX/ethanol engine developed by the Akronauts Rocket Design Team, into the Copperhead launch vehicle. The objective is to design, build, and test a complete propulsion system including electronics, software, pressurization, tanks, and instrumentation capable of flight. A key innovation is the electronic pressure regulation system, which replaces mechanical regulators with servo-actuated valves running PID loops for precision and an extra degree of control.

The Stinger engine, under development since Fall 2023, has undergone nine hot-fire tests, with further testing planned to qualify the new …

Computational Study Of Rotating Detonation Combustors, Aditya Balasubramaniam

Mechanical and Aerospace Engineering Theses

Rotating detonation combustors (RDCs) are pressure-gain combustion devices that sustain one or more continuously rotating detonation waves, offering potential thermodynamic and performance advantages over conventional deflagration-based systems. Their behavior depends strongly on combustor geometry and operating conditions. Understanding these effects is therefore essential for the design and optimization of practical RDCs. Accordingly, this thesis numerically investigates annular RDCs with two primary objectives: (1) to evaluate the effects of propellant mass flux and (2) to assess the influence of annular width on detonation-wave dynamics and combustor performance.

A finite-volume framework is used to solve the compressible reactive Euler equations with hydrogen–air …

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 …

Numerical Investigation Of Injector Location And Equivalence Ratio In A Flame‐Holder Cavity Scramjet, Matthew Sorenson

Electronic Theses and Dissertations

This thesis presents a CFD-based parametric study of injector location and fuel rate in an ethylene-fueled flame-holder cavity scramjet using STAR-CCM+. Simulations are performed for three injector locations (x/D = 18, 36, and 54) and nine equivalence ratios spanning from ϕ = 0.2 to 1.0 in 0.1 increments. The study aims to determine how injector placement and fueling level alter scramjet performance across a broad operating sweep. The results show a clear regime change between ϕ = 0.2 and ϕ ≥ 0.3. At ϕ = 0.2, combustor behavior is weakly sensitive to injector location compared to the higher-fueling cases. For …

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 …

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 …

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 …

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 …

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 …

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 …

Thermal Management With Supercritical Carbon Dioxide Under Extreme Applications, Devon Hardy

Doctoral Dissertations and Master's Theses

A unique challenge in thermal system design is minimizing the power required to operate cooling systems while maintaining effective heat removal. Traditional cooling systems utilize single-phase fluids where the heat transfer mechanisms are well understood. To meet a variety of cooling demands, a range of technologies are available, including microchannel forced convection, jet impingement, porous media, nanofluids, pin fin arrays, and film cooling, each offering distinct advantages and limitations. While the performance of single- or two-phase cooling systems are generally predictable, in extreme thermal environments, new cooling solutions are needed to improve overall system efficiency and reliability.

Supercritical fluids, particularly …

Numerical Study On Flow Separation And Performance Characteristics Of Slot Nozzle, Chase Charpentier

Doctoral Dissertations and Master's Theses

The altitude compensating nozzle (ACN) is a type of rocket nozzle or engine that tries to minimize the negative effects of overexpansion at low altitudes. There are many forms of ACN's but most of them are heavier than traditional bell nozzles, alter the geometry of the nozzle, which requires extensive research into optimizing the new geometry, or require complex systems that can lead to structural, heating, or material problems. Out of the ACN's, the slot nozzle is a passive ACN that builds upon the bell nozzle and requires no additional weight or complex systems.

This slot nozzle is comprised of …

Characterization Of Cooled Turbine Efficiency For Off-Design Performance Models, Alberto Garcia

Doctoral Dissertations and Master's Theses

Gas turbine performance modeling is essential for predicting engine behavior across design and off-design conditions. Yet the treatment of cooling or service flows remains inconsistent, as these streams interact with the main flow in complex ways and their contribution to turbine work depends on how they are represented in performance models. The challenge is especially present in “black-box” approaches, where only inlet and outlet conditions are known and engineers must decide whether to introduce cooling flows upstream (if performing useful work) or downstream (if not). This thesis examines how different definitions of isentropic power and cooling-flow treatment affect the apparent …

Thermally Perfect Augmentation Of A Supersonic Inlet Design Tool That Uses Method Of Characteristics, Mario V. Guardado

Master's Theses

This work is the first in a series to augment a supersonic air inlet design tool based in Python 3 to incorporate new models that increase the range of applicability of the tool. This effort focuses on improving the thermodynamics model by incorporating a thermally perfect gas model. This tool utilizes method of characteristics to solve the governing equations for an inviscid, irrotational, isentropic, steady, supersonic flow field. Multiple test cases are used to assess the accuracy of all new models. A comparison is made between the original code’s test case for a supersonic inlet at low temperatures to verify …

Analysis Of The Effects Of Extractor Orientation On The Performance Of An Electrospray System, Hannah Grace Sargent

Masters Theses

In this thesis, a single-emitter porous electrospray thruster was tested at nine different extractor electrode positions. The nine positions were: center, four slightly offset in each cardinal direction, and four significantly offset in each cardinal direction. Slightly offset was defined as ~25% of the distance from the center to the edge of the extractor orifice (~125 ± 2 μm) and significantly offset was defined as ~60% of the distance from the center to the edge of the extractor orifice (~302 ± 2 μm). Three diagnostic measurements were recorded to determine the effect of the extractor electrode position on thruster operation: …

A Feasibility Study On Series Hybrid-Electric Propulsion For Narrow-Body Transport Aircraft, Carver J. Glomb

Master's Theses

As global climate change accelerates, the reduction of carbon emissions has become a critical objective across multiple industries. The aviation sector, however, has lagged behind other transportation domains in implementing sustainable alternatives, despite growing demand for air travel. Recent research and emerging technologies have proposed several decarbonization pathways, including hydrogen fuel, sustainable aviation fuels (SAFs), and hybrid or fully electric propulsion systems. Among these, series hybrid-electric propulsion has received comparatively limited attention, particularly for application in transport-class aircraft. This study investigates the feasibility and emissions-reduction potential of a series hybrid-electric propulsion architecture applied to a representative narrow-body platform. A Python-based …

Development And Testing Of A Lab-Scale Resonance Igniter For Rocket Propulsion Applications, Aidan Caplan

Master's Theses

The resonance igniter is a type of rocket engine ignition system that initiates spontaneous combustion without using an external ignition source. This is possible because the activation energy needed for the combustion reaction to take place is provided by the igniter as it receives propellant flow. This can simplify the igniter hardware and lends it high re-usability while enabling the use of high-efficiency propellant combinations. Its potential benefits could make it a desirable alternative to traditional approaches such as using spark igniters or hypergolic propellants. The present research strove to inaugurate the study of the resonance igniter at Cal Poly …

Model-Based Design Of Compressed Lithium-Metal Pouch Cell Battery Modules For Evtol Applications, Scott J. Stirling

Master's Theses

Batteries with higher specific energy and power are essential for extending the range and performance of electric vertical takeoff and landing aircraft (eVTOLs). Anode-free lithium-metal pouch cells offer strong potential at the cell-level but require high compressive pressures to enhance cycle life and discharge performance. These pressures necessitate heavier structural components, reducing packaging efficiency at the module level.

To evaluate this tradeoff, a full-factorial enumeration model was developed to explore viable module designs within a constrained packaging volume. The model scales subsystem masses, enforces design rules and material limits, and accounts for large (~20%) cell thickness changes during cycling.

Results …

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 …