Aerodynamics and Fluid Mechanics Commons^™

Influence Of The Sst K-Ω Stress-Limiter Coefficient On Transonic Shock Buffet Prediction For The Oat15a Supercritical Airfoil, Melinawo Vowotor

College of Graduate Studies: Theses & Dissertations

Transonic shock buffet predictions using the Shear Stress Transport (SST) k–ω turbulence model are known to be sensitive to the stress-limiter coefficient a₁, yet no systematic investigation of this sensitivity exists. This thesis presents a parametric study of a₁ for two-dimensional URANS simulation of shock buffet on the OAT15A supercritical airfoil at M = 0.73 and Re = 3 × 10⁶. Eleven a₁ values (0.25–0.37) are examined at α = 3.5°, and a matrix of five a₁ values across five angles of attack (3.0°–3.9°) maps the interaction with incidence. The results reveal that a₁ acts as a bifurcation parameter: a …

Modeling Hepa Filter Media Performance And Evaluation Of Filtration Leak Test Success, Daniel M. Abraham, Steven J. Eckels, Shahin N. Amiri

Civil & Environmental Engineering Faculty Publications

This research presents a cost-effective microscale modeling analysis of high-efficiency particulate air (HEPA) filter media. We analyzed leak-free and leaking media with known leak sizes. A three-dimensional fibrous model with non-homogeneous fiber diameters (0.2–2 µm) and a packing density of 7.5% was developed to replicate a HEPA filter sheet (H14) microstructure. The objective was to simulate and analyze the pressure drop and collection efficiency of nanofibrous media for aerosol particles with a diameter of d_p ≤ 0.5 µm. The results were compared to prior experimental and theoretical models, exhibiting a high level of agreement with pressure drop and efficiency …

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 …

Design, Construction, And Initial Testing Of A Oxy-Acetylene Testing Facility, Blake Bowman, Davide Viganò

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Thermal Protection Systems (TPS) are critical for atmospheric re-entry and hypersonic flight vehicles, yet ground-based evaluation of TPS materials remains challenging due to the cost, complexity, and limited availability of large arc-jet and inductively coupled plasma (ICP) facilities. Oxy-acetylene testing provides a low-cost and accessible alternative for preliminary material screening, sensor development, and fundamental studies of material response under high heat-flux conditions. This paper presents the design, construction, and initial validation of the High-Enthalpy Acetylene Testing (HEAT) facility at Missouri University of Science and Technology. The facility incorporates a modular experimental architecture, independently controlled oxygen and acetylene mass-flow systems, and …

Tomo-Piv Study Of Baseline Flow Structures Behind A Strut Injector, Josiah Mcdermott, Connor Bell, Davide Viganò

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Stabilizing combustion in scramjet engines is a formidable challenge due to the small-time scales afforded for air-fuel mixing. Numerous studies in this area have demonstrated the potential of strut-style platforms for fuel injection and mixing enhancement, which remains an active area of research. In the Aerodynamics Research Laboratory at Missouri S&T, a strut-style injector system has recently been installed. In this study, we characterize the baseline flow structures behind this platform absent fuel injection. The wake generated by a strut itself has an appreciable impact on the resulting air-fuel mixing, which motivates its characterization. In future studies, this characterization will …

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 …

Increasing Actuation Authority And Bandwidth For Aeromechanics Testing: A Piezoelectric-Based Approach, Sydney A. Giannuzzi

Graduate Studies Theses and Dissertations 2026

Flutter in turbomachinery poses significant risks to aerospace systems, requiring accurate identification of flutter boundaries to ensure operational safety. Traditional binary “flutter / no flutter” testing methods provide limited data without error margins. Aeromechanical Identification Methodology (AIM) offers a safer alternative by mapping aeromechanical damping across operational conditions using non-contact excitation. However, current AIM actuators are constrained to excitation frequencies below 500 Hz, limiting their effectiveness and applicability. To bridge this gap, this research analyzed and validated performance of a novel piezoelectric-based oscillatory flow injection valve (NOVA) designed to deliver high-bandwidth, high-authority actuation for expanded flutter boundary mapping.

NOVA was …

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, …

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 …

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 …

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 …

Enhanced Atomization And Combustion In Subsonic Ljic Systems Using Ultrasonically Driven Solid Obstructions, Daniel Sebastian Cruz

Graduate Studies Theses and Dissertations 2026

The liquid fueling methods used in aircraft propulsion have undergone extensive optimization, with Liquid Jets in Crossflow (LJIC) emerging as a simple yet effective injection scheme. LJIC enables sufficient fuel mass flow rates and penetration for high-speed operation, however fuel trajectory and droplet size remain highly sensitive to crossflow conditions. As a result, wide flight envelopes introduce variability in atomization, leading to unsteady combustion performance. Recent work has incorporated a pintile, a solid obstruction placed in the path of the fuel jet, to redistribute momentum and reduce trajectory variability across varying flow conditions. While this approach improves trajectory uniformity, it …

Numerical And Experimental Evaluation Of A Simple, Low-Energy Lunar Volatile Separation Technology, Eleanor L. Zimmermann

Dissertations, Master's Theses and Master's Reports

In-situ resource utilization (ISRU) is the practice of finding, extracting, and using the local resources found on extraterrestrial bodies, such as the Moon and Mars. ISRU enables in-situ production of mission consumables—such as rocket fuel and potable water—which will be critical for establishing a sustainable human presence on the Moon, a goal NASA intends to accomplish by 2028 with the Artemis missions. The separation and liquefaction of locally extracted volatiles—such as water, CO₂, and Methane—is an essential component in lunar surface sustainability, but there are very few technologies being developed for this purpose. This report introduces the Radiative …

On The Vibrational Dynamics Of Wind Turbine Blades: The Oscillatory Response To Gust Pulses, And The Physical Mechanisms Behind Them, North A. Yates

Dissertations, Master's Theses and Master's Reports

An easily noticed trend in the utility-scale wind turbine industry is that the size of the machines has continued to increase over time. While this may have benefits in terms of increasing the power generation for a single turbine, a major drawback is the rate with which the weight of the turbine blades grow. To ensure these larger machines can be utilized, efforts are being put forth to create lighter blades. This may fix the weight issue, but brings on a new one; these lighter blades can also be more flexible than previously studied ones. It is, therefore, vitally important …

Pressure Field Estimation From 2d-Piv Measurements: A Case Study Of Fish Suction-Feeding, Jensine C. Coggin, Duvall Dickerson-Evans, Erin E. Hackett, Roi Gurka

Physics and Engineering Science

Particle image velocimetry (PIV) flow measurements are common practice in laboratory settings in a wide variety of fields involving fluid dynamics, including biology, physics, engineering, and medicine. Dynamic fluid pressure is a notoriously difficult property to measure non-intrusively, yet its variation is a driving flow force and critical to model correctly. Techniques have been developed to estimate the pressure from velocity and velocity gradient measurements. Here, we highlight a novel application of boundary conditions when applying such pressure estimation techniques based on two-dimensional PIV data; the novel method is especially relevant to problems with complex boundary conditions. As such, it …

Wind Tunnel Instrumentation And Testing, Nicholas Marek, Abraham Mezera, Laura Jin, Hayden Smith, Curtis Cook

Student Scholar Symposium

The Raymond B. Jones College of Engineering was contacted by an automotive engineering firm seeking to use the college’s wind tunnel for gathering data on the aerodynamic performance of a proprietary prototype automotive door. Specifically, the client requested the quantification of the drag coefficient of the model at extreme wind speeds. The drag coefficient, a dimensionless number that quantifies the resistance of a specific geometric shape to airflow, will be a valuable datapoint for the client’s design iteration. Due to the sensitive nature of their work, the client has wished to remain anonymous. RBJCOE professors tasked a senior design team …

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 …

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 …

Propeller Noise Prediction Of An Urban Air Mobility Vehicle In Urban Environment, Jie Hua

Doctoral Dissertations and Master's Theses

Urban Air Mobility (UAM) vehicles operate in complex, unsteady aerodynamic environments where wake interactions, gust and turbulence significantly affect both performance and noise generation. Understanding these mechanisms is critical for developing quieter and more efficient eVTOL systems that meet future community noise and certification requirements. This dissertation focuses on the high-fidelity numerical investigation of propeller noise in three representative unsteady loading scenarios: (i) transition (tilt) flight, (ii) edgewise inflow, and (iii) wake–propeller interaction. Each case emphasizes different physical mechanisms that dominate noise generation in UAM operations. Hybrid turbulence-resolving approaches—Detached Eddy Simulation (DES) and Delayed Detached Eddy Simulation (DDES)—are coupled with …

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 …