Aerodynamics and Fluid Mechanics Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

Structural Design And Development Of Deployable Propeller Blade, Annan Mashin

Graduate Studies Theses and Dissertations 2026

Aerospace systems frequently face competing requirements between compact packaging and high aerodynamic performance. Large propellers improve efficiency and thrust generation, yet launch constraints and confined storage volumes limit their maximum span. Conventional deployable solutions rely on hinges, locking mechanisms, and external actuation, increasing mechanical complexity and reducing reliability. This dissertation investigates an alternative approach in which elastic instabilities in thin composite shells are deliberately harnessed to enable rapid, mechanism- free deployment of aerodynamic structures. This work harnesses propagating instability in open- section thin-walled airfoil geometries to enable reversible transformation between compact stowed and stiff deployed configurations. By tailoring structural architecture, …

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 …

Ignition Delay Time Measurements Of Natural Gas/Ammonia Mixtures At Gas Turbine Operating Conditions, Zachary A. Morris

Graduate Studies Theses and Dissertations 2026

Natural Gas/Ammonia (NG/NH₃) fuel blends are a promising route to reduce CO₂ emissions from gas turbines while leveraging existing NG infrastructure, but their autoignition behavior at elevated pressures is not yet well constrained. This work reports high-pressure shock tube ignition delay time (IDT) measurements for NG/NH₃/Air mixtures at gas turbine-relevant conditions. Experiments were performed at pressures of 5, 10, and 25 bar, temperatures from 1500 to 2100 K, with equivalence ratios of Φ = 1.0, 1.2, and 1.4, and argon-diluted fuel compositions spanning pure NH₃ to NG-rich blends. Experiments were carried out in two …

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 …

Fundamental Chemical Kinetic Experiments Of Combustion Products Inside A Shock Tube, Alex-Abraham Pothen

Graduate Thesis and Dissertation 2023-2024

The use of lateral divert thrusters on hypersonic vehicles would allow for fine-tuned attitude control at high Mach numbers. However, the jet interaction effects of lateral thrusters on the hypersonic flow field have not been investigated thoroughly. Computational Fluid Dynamics (CFD) can provide preliminary modeling of the jet interaction, but several variables such as vehicle geometry, velocity, and altitude, result in computationally expensive modeling or loss in accuracy of the results. Therefore, the goal of chemical kinetics testing and chemical model verification is to enhance the fidelity of the jet interaction effects, specifically the plume reaction with air and the …

Analysis Of Variations In Flow-Independent Liquid Jet-In-Crossflow Injections, Michael Scott

Honors Undergraduate Theses

Liquid fuel injection is a critical mechanism for the deliverance of liquid fuel in contemporary aircraft propulsion combustion systems due to its outsized influence in providing optimal combustion conditions and improving overall aircraft efficiency and performance. Despite this, these liquid jet in crossflow (LJIC) systems are highly variable due to conditions in the jet and the surrounding airflow, leading to variability in performance behavior and inconsistency in fuel mixing and combustion efficiency. This has prompted the introduction of solid pintile obstructions of novel designs to provide a more flow-independent fuel injection scheme and decrease variability of the jet properties against …

The Performance Of A Liquid-Fueled High Pressure Igniter For Scramjets, Gerardo Rodriguez

Electronic Theses and Dissertations, 2020-2023

Ignition systems within scramjet combust ors remain a trending topic of research because of the essential role they play in the engine's operation. An alternative to currently researched ignition systems is investigated in this study with the main goal of u tilizing the same liquid fuel as the mai n combustion chamber for the ignition system itself. In this case, JetA fuel was injected in a liquid jet in crossflow configuration with air to atomize the fuel. To characterize this ignition system, metrics such as combustion chamber pressure rise, pulse frequency, and jet penetration were used to validate possible utilization …

A High-Pressure Shock Tube Study Of Hydrogen And Ammonia Addition To Natural Gas For Reduced Carbon Emissions In Power Generation Gas Turbines, Michael Pierro

Electronic Theses and Dissertations, 2020-2023

Ignition delay times from undiluted mixtures of natural gas (NG)/H2/Air and NG/NH3/Air were measured using a high-pressure shock tube at the University of Central Florida. The combustion temperatures were experimentally tested between 1000-1500 K near a constant pressure of 25 bar. Mixtures were kept undiluted to replicate the same chemistry pathways seen in gas turbine combustion chambers. Recorded combustion pressures exceeded 200 bar due to the large energy release, hence why these were performed at the high-pressure shock tube facility. The data is compared to the predictions of the NUIGMech 1.1 mechanism for chemical kinetic model validation and refinement. An …

Flow Induced Vibration In Corrugated Metal Flexhoses, Patrick Tran

Electronic Theses and Dissertations, 2020-2023

This study on flow-induced vibration provides valuable insights into the fundamental dynamics of fluid-structure interactions. The findings contribute to the development of predictive models and design guidelines for engineering systems susceptible to flow-induced vibration. By improving our understanding of this phenomenon, engineers can enhance the safety and reliability of various structures subjected to fluid flow, such as pipelines, flexhoses, and bellows. Flowinduced vibration is a phenomenon that occurs when fluid flow interacts with a structure, leading to oscillations and potentially causing mechanical damage. Understanding the underlying mechanisms and predicting the vibration characteristics is crucial for the design and safe operation …

A Study Of The Influence Of Heat Flux On Aerodynamics In Hypersonic Flow, Kristina Pionessa

Electronic Theses and Dissertations, 2020-2023

This study investigates the utilization of computational fluid dynamics (CFD) to simulate aerodynamic heating effects in support of research and design endeavors. The initial investigation demonstrates the effectiveness of a computational approach in analyzing different geometries and flow conditions. Specifically, CFD is employed to analyze the aerodynamics of a blunt cone, double cone, and hypersonic leading edge experiencing a changing heat source across the flow/body boundary. At the stagnation point, maximum thermal loading occurs as previously found; therefore, boundary layer thickness and shock standoff distance is measured at that position to compare the results of each case. Characteristics such as …

The Effects Of Microgravity On The Development Of Osteoporosis, Jackson Asiatico

Electronic Theses and Dissertations, 2020-2023

Previous research has identified a potential link between microgravity conditions and the onset of osteoporosis, a connection that stems from altered fluidic pathways crucial in nutrient dispersion and cell stimulation. Specifically, the absence of mechanical loading in space environments reduces fluid shear stress, thereby disrupting the normal flow of interstitial fluid in trabecular bone. This disruption greatly impacts the functionality of osteoblasts and osteoclasts, the vital cells responsible for maintaining healthy bones. The focus of this study aims to explore the impact of microgravity on bone loss in astronauts, establishing the connection between the lack of mechanical loading and the …

A Study Of The Performance Of Wind Turbines Fitted With Sprayed Liquid Flaps, Alexander Spitzer

Electronic Theses and Dissertations, 2020-2023

Lift generating technologies are often considered a potential solution to increased power generation and reliability within wind turbine design. The Sprayed Liquid Flap (SLF) is a novel active control method that has shown success in providing lift generation on aircraft wings, but its application in the context of rotating flows is unexplored. This research aims to understand the effects of the SLF on a wind turbine and provide a pathway for future exploration of its aerodynamic impacts on rotating flows. Computational Fluid Dynamics with an Euler-Euler multiphase approach is employed to assess the influence of the SLF on a wind …

The Numerical Study Of Aeroacoustics Performance Of Wings With Different Wavelength Leading-Edge Tubercles, Youjie Zhang

Honors Undergraduate Theses

The leading-edge tubercle is a type of airfoil modification that inspired by the humpback whale. It was found that the aerodynamic performance of the wing would increase compared to the wing without tubercles. In the past several years, a lot of numerical and experimental studies have been accomplished to explore this leading-edge modification. Besides the aerodynamic performance change, this research explores the aeroacoustics behavior of airfoils with leading-edge tubercles. A numerical study based on Computational Fluid Dynamics (CFD) is established, and simulations using Star CCM are accomplished based on reasonable set-ups. The airfoil chosen to create the wing is NACA …

Design Considerations And Imaging Setup For Liquid Fuel Droplet Detonation Wave Experiments, Nicolas Berube

Electronic Theses and Dissertations, 2020-2023

Initial results, design considerations, and experimental validation of a new detonation tube are presented to further improve detonation wave interaction research. The new structure consists of four independent portions: the deflagration to detonation initiation section, transition expansion section, operating test section, and dump section. The initiation, transition, and test sections are designed to operate within a temperature limit of 150°C and a maximum detonation pressure of 100 bar. The test section is comprised of interchangeable 155 cm stainless steel 316 plates assembled to create a 10x10 cm square hollow structure, sealed with longitudinal O-rings between plates and lateral O-rings between …

An Evaluation Of Thermocouple Reconstruction Techniques, Derek Brauneis

Electronic Theses and Dissertations, 2020-2023

Temperature measurements can be difficult to obtain across many different harsh environments such as engine combustion chambers, engine exhaust temperatures, and explosion fireballs. While there are alternate methods to measure fluid temperature such as laser measurements, acoustic measurements, and camera imaging techniques, these methods can often be expensive, difficult to implement, and not able to see within the environment. Thermocouples are popular sensors because they are cheap and easy to implement across a wide range of applications and can measure temperature in areas where other methods cannot reach or see. However, while these sensors are very popular and versatile, they …

Rotorcraft Lander Fixed To A Descending Capsule Backshell, Corey Zucker

Electronic Theses and Dissertations, 2020-2023

NASA is financing a mission to study the surface of Titan, Saturn's largest moon, to investigate the terrain, chemical compositions, and potential for existent life. This mission is an exciting advancement from Mars Ingenuity, because the quadrotor lander, Dragonfly, will be the first of its kind with four coaxial rotors. Upon entry into Titan, and at near surface atmospheric conditions, Dragonfly will exit a parachute supported backshell that has shed its protective heatshield. The aerodynamics of this state are significant in comprehending the dynamics of the overall system for successful deployment into powered flight. The studies presented here examine the …

Hypersonic Aero-Optic Measurements In A High-Pressure Shock Tube, Jonathan P. Mcgaunn

Graduate Thesis and Dissertation 2023-2024

The high-pressure shock tube facility (HiPER-STAR) at the University of Central Florida (UCF) is analyzed experimentally to demonstrate the practicality of hypersonic aero-optical testing in an impulse facility without the use of an expansion nozzle or acceleration tube. The investigation analyses driver gas blending with helium and hydrogen to raise the speed of sound ratio in an attempt to increase the Mach number for aero-optics testing. HiPER-STAR has a unique ability to withstand pressures up to 1000 atm and run in a double diaphragm configuration allowing for a significant pressure differential to be created between the driver and driven sections. …

Thermal Management Strategies For Hypersonic Flight: Supercritical Co2 Jet Impingement Cooling Investigation For Leading Edge, Manoj Prabakar Sargunaraj

Graduate Thesis and Dissertation 2023-2024

This study addresses the critical need for effective thermal management in hypersonic vehicles facing intense heat at their leading edge due to high enthalpy flow. The objective is to propose an active impingement cooling system that ensures the structural stability and performance of these vehicles. This dissertation presents an in-depth exploration of the numerical simulations conducted on the hypersonic leading edge, focusing on a 3mm radius with active cooling utilizing supercritical carbon dioxide (sCO2) as the coolant. The research incorporates conjugate simulations that merge external hypersonic flow and sCO2 active cooling. Utilizing a thermodynamic non-equilibrium two-temperature model and various chemical …

An Optimization Study Of Small-Scale Propeller Blade, Fahad M. Nabid

Honors Undergraduate Theses

This research paper aims to investigate the optimization of smaller propeller blades to achieve maximum efficiency by studying the effect of the twist angle on reducing drag, increasing thrust, and preventing rapid wear on the blade. Inefficient propellers consume a significant amount of energy, particularly during low-speed flights. The low Reynolds number regime challenges aviation engineers to design propellers with the highest possible efficiency to minimize energy losses. The primary objective of this thesis is to optimize smaller propeller blade shapes to enable them to produce maximum efficiency. The advanced ratio of a propeller blade heavily influences the blade's performance …