Aerospace Engineering Commons^™

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 …

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 …

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 …

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 …

Experimental And Numerical Study On The Stability Limits Of Ammonia And Ammonia/Hydrogen Flames Inside A Toroidal Jet-Stirred Reactor, Guillermo Alberto Barrios Cadenas

Graduate Studies Theses and Dissertations 2026

Ammonia’s (NH₃) properties as a carbon-free hydrogen carrier, its phase characteristics, and its wide global infrastructure present a solid case as a potential surrogate for carbon-based aviation fuels. Delivering a zero-emission NH₃-based engine requires careful integration and optimization of the combustor and thermal management systems, a process that requires high-fidelity chemical reacting models experimentally validated through the use of simplified combustors. This study investigates NH₃ fundamental combustion characteristics at conditions relevant to aviation gas turbines using a newly constructed toroidal jet-stirred reactor (TJSR) facility. Lean blow-off (LBO) experiments were carried out for NH₃ blends …

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 …

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 …

Temperature And Speciation Measurements Of Aluminum-Laden Detonation Flows Via A Three-Color Wavelength Modulation Spectroscopic Sensor, Marc B. Etienne

Graduate Studies Theses and Dissertations 2026

Tunable diode lasers are widely used and are known to be great options for continuous wave lasing applications. Because of their stability and spectral selectivity, they have become an important diagnostic tool for modern combustion research. Previous combustion research, particularly those focused on solid and hybrid rocket systems, have shown that the interaction of aluminum with a reacting flow can greatly affect the dynamics and the thermochemical properties of the surrounding gas, therefore understanding the effects of aluminum-laden flows is critical for the advancement of these propulsion systems. However, due to the high degree of optical interference, high temperatures, and …

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 …

Detonability Limits Of Liquid Fuel Cloud, Khaoula Chougag

Graduate Studies Theses and Dissertations 2026

Detonation-based propulsion systems are of significant interest owing to their high thermodynamic efficiency, rapid energy release, and favorable entropy production relative to deflagration-based systems. Liquid fuels offer practical advantages in storage and volumetric energy density, making them attractive candidates for next-generation detonation engines. This dissertation investigates the detonability characteristics of liquid hydrocarbon fuel clouds through three interconnected studies conducted in a turbulent shock-tube environment using high-speed imaging and pressure diagnostics. The first study maps the detonability limits of monodisperse n-dodecane clouds by systematically varying droplet diameter (5-50 μm) and O₂/N₂ oxidizer composition at equivalence ratios spanning ϕ = 0.8-2.0. Results …

Anisotropic Second-Harmonic Ince-Gaussian Beam Generation Using Nbobr2 Holograms, Jayanta Deka, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ince-Gaussian (IG) modes are a complete and orthogonal set of solutions to the paraxial wave equation in elliptic coordinates representing a continuous transition between Hermite-Gaussian modes and Laguerre-Gaussian modes. Chip-scale platforms to generate IG beams have great significance for various applications, including optical trapping and micromanipulation of particles, optical communication, and quantum optics. On the other hand, materials with high optical anisotropy are crucial for building polarization-sensitive optical devices. In this context, niobium oxide dihalides are a new class of ferroelectric materials exhibiting strong, tailorable, and highly anisotropic second-harmonic generation responses. Here, we report the generation of highly anisotropic second-harmonic …

Supersonic Wind Tunnel Free Stream Turbulence Characterization Using 2-Point Focused Laser Differential Interferometry, Joseph Villarreal, Joshua Gary, Davide Vigano

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Non-intrusive laser-based diagnostics, such as Two-Point Focused Laser Differential Interfer-ometry (2-FLDI), play a crucial role in modern aerodynamic research by enabling simultaneous measurements of density and velocity in compressible flows. A 2-FLDI system has been developed and implemented for the Missouri S&T Supersonic Wind Tunnel to characterize free stream turbulence fluctuations and free stream convective velocity. Design choices that enabled the 2-FLDI to overcome low turbulence to measure free stream velocity are detailed. The free stream velocity measurements are validated against previous particle image velocimetry data, showing good agreement. Analysis of normalized velocities and density-based turbulence intensities found that the …

Upconversion Photoluminescence In Wsse Alloy Monolayer Under Uniaxial Tensile Strain, Shrawan Roy, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The optical responses of monolayer transition metal dichalcogenides (1L-TMDs) can be tuned effectively by using mechanical strain. In this work, the tuning of upconversion photoluminescence (UPL) emission in 1L-WSSe alloy by applying uniaxial tensile strain is investigated. When the uniaxial tensile strain is changed from 0 % to 1.02 %, the peak position of UPL emission has a redshift of around 25.6 nm, and the UPL intensity goes up with an exponential function of the applied strain as the upconversion energy difference is varied from −197 meV to −131 meV. The sublinear power dependence for UPL emission in 1L-WSSe alloy …

Physics-Constrained Generative Adversarial Networks For Dimensionality Reduction In Optimization, Samuel Sisk, Xiaosong Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric vertical takeoff and landing (eVTOL) aircraft make a unique form of urban air mobility due to their low noise, zero emission, and precision control. To maximize efficiency, high-fidelity simulation-based multidisciplinary design optimization discovers the optimal balance among subsystems within an eVTOL. However, conventional multidisciplinary design optimization is computationally intensive due to excessive high-fidelity model evaluations. Moreover, complex nonlinear constraints deteriorate optimization efficiency and convergence. While surrogate models enable efficient design optimization, surrogate modeling suffers in large-scale applications and surrogate-based optimization still has to deal with nonlinear constraints. To address these challenges, the authors' previous work proposed physics-constrained generative adversarial …

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 …

Optimal Takeoff Trajectory Prediction Of Electric Drones Based On A Fully Automated Optimal Experimental Design Method, Jiachen Wang, Dheeraj Paramkusham, Xiaosong Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric vertical takeoff and landing (eVTOL) aircraft is attracting great interest as a viable solution to promote urban aerial mobility with promising flexibility as well as emission reductions. However, the low specific energy of the current battery is still a strong constraint on the range and endurance of eVTOL flights, especially considering the significant power demands during the takeoff process. Engineering design optimization permits promising solutions for the minimum takeoff energy consumption but can be computationally intensive due to iteratively evaluating simulation models. Surrogate-based design optimization is efficient but still relies on optimization iterations which prohibit real-time decision-making. To fill …

Distributed Vibration Sensing For Identification Of Loose Connectors In Coaxial Data Transmission Lines, Saidanvar Esanjonovich Valiev, Anthony C. Okafor, Jeremiah J. Rittenhouse, Jie Huang, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This study investigates the effect of vibration-induced loose connections on signal reflection (S11) for loose connection identification in aerospace coaxial cables using distributed sensing approach, which is effective in filtering the noise and identifying minor discontinuities. In this approach, a sliding gated window is applied to S11 signal, a fast Fourier transform is performed over the gated windows, cross-correlation is computed between the baseline and vibration-affected signals, and the standard deviation is mapped along the cable length. Sinewave signals from 9 kHz to 5 GHz were swept through cables with vibrating connectors under three conditions: fully tightened, loosened by 180°, …

Multiphysics Modeling Of Melt Pool Dynamics And Powder Bed Stability In Lpbf Of Inconel 718 For A Circular Cavity, Nayan Pundhir, Oluwapelumi O. Adejumo, Kumbla Chandrashekhara, Joseph W. Newkirk, Heath Misak, Cesar Ortiz Rios

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a metal additive manufacturing process in which a concentrated laser beam selectively melts successive powder layers to fabricate components. Final part quality is highly sensitive to process parameters such as hatch spacing, powder bed density, laser power, and scanning speed. In this study, a computational fluid dynamics model employing discrete element method has been developed in FLOW-3D to simulate LPBF of Inconel 718. The modeled powder bed incorporates particle size distribution data obtained from scanning electron microscopy and is evaluated for single-layer, single-track deposition over a circular cavity. The model captured melt pool dynamics …

Performance Evaluation Of Thick Carbon Fiber-Reinforced Laminates Manufactured Using Six-Magnetron Microwave System, Nayan Pundhir, Sourav Bolar, Kumbla Chandrashekhara, Kristen Donnell, Jim Lua, Kalyan Shrestha, Rui Li

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microwave curing is a fast, energy-efficient, and a viable alternative to conventional thermal curing processes. It has been widely adopted for processing carbon fiber-reinforced polymer composites because the high electrical conductivity of carbon fibers enables strong microwave coupling. In this study, IM7/Cycom 5320-1 unidirectional prepreg has been used to fabricate 64-layer laminated composites. Symmetric cross-ply ([0°/90°]16S) and a quasi-isotropic ([45°/90°/−45°/0°]8S) layup have been investigated. A custom-built six-magnetron microwave applicator and an autoclave were employed to manufacture the composite panels. Degree of cure of the manufactured laminates was evaluated via differential scanning calorimetry. Interfacial bonding and porosity of the microwave-cured laminates …

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 A Parallel Two-Dimensional Jet In Supersonic Flow, Josiah Mcdermott, Connor Bell, Davide Vigano

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Stabilizing combustion in supersonic flows 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 flow structures behind this platform in a range of injection pressures and corresponding mass flux ratios. The wake generated by a strut and injection plume, even absent combustion or mixing enhancement geometry, has an …

2-Point Focused Laser Differential Interferometry Measurements Of A Parallel Jet In Supersonic Flow, Joshua Gary, Joseph Villarreal, Davide Vigano

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Turbulence in compressible flows plays a central role in applications such as air-fuel mixing in supersonic combustors and is significantly more complex than incompressible turbulence due to the presence of fluctuating thermodynamic quantities. As such, models like the Strong Reynolds Analogy (SRA) are used to relate these quantities. However, SRA validity has been examined primarily in boundary-layer flows. In this work, a newly developed Two-Point Focused Laser Differential Interferometry (2-FLDI) system is implemented in a two-dimensional parallel supersonic jet. The diagnostic is described in detail, including optical alignment procedures, calibration methods, and data analysis techniques. Measurements acquired at multiple streamwise …

Corrigendum To “3d Semi-Analytical Thermo-Elasto-Plastic Model For Additive Manufacturing”(Additive Manufacturing, (2026), 127, C, (105308), (S2214860426002344), 10.1016/J.Addma.2026.105308), Tao Liu, Ming C. Leu, Edward C. Kinzel, Chinedum Okwudire

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The author regret about the correction in the Equation B(1) in original article. The corrected version of the Equation B(1) is given below,(1.1)∂uxxx,ξ∂x=116πμ1−ν4ν−1x−ξxR3−3x−ξx3R5−8ν−5x−ξxR13+34ν−3x−ξx3R15−18x−ξxzξzR15+30x−ξx3zξzR17−12ν−12ν−1x−ξxR1R1+z+ξz2+4ν−12ν−1x−ξx3R13R1+z+ξz2+8ν−12ν−1x−ξx3R12R1+z+ξz3 The authors would like to apologise for any inconvenience caused. DOI of original article: < 10.1016/j.addma.2026.105308>

Multiphysics Simulation And Experimental Validation Of Phase Transformation And Hardness In Jominy End-Quenched Low-Alloy Steels, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. A. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

High-volume industrial continuous hot-rolled steel heat treatment processes involve sophisticated multi-phase modeling. The performance of a given process can be optimized by coupling phase transformation kinetics with the cooling conditions of the process. This study develops a multiphysics model to simulate an intensive quenching process for steel, which is inherently transient and highly dependent on numerous parameters. The simulated object was a Jominy end-quenched specimen geometry using two commercial steels, AISI 4130 and AISI 4140, with the goal of transferring a verified methodology to the heat treatment process for industrial heavy-section products (bars, slabs). The simulation employs thermal, mechanical, and …

Simulated Lunar Gravity Testing Of A Magnetic And Electrostatic System For Beneficiating Lunar Regolith, Blake A. Coffman, Gabriel Porter, Lindsay Manteufel, Mitchell Cottrell, Jeffrey D. Smith, David J. Bayless, William Shonberg, Frank D. Han, Fateme Rezaei, Kirby Runyon

Materials Science and Engineering Faculty Research & Creative Works

We present the design and testing of a lunar regolith beneficiation device that utilizes magnetic and electrostatic separation methods to concentrate desired minerals by removing unwanted material, such as the mineral anorthite, from bulk lunar regolith. The beneficiated materials would have value for downstream in-situ resource utilization (ISRU) processes such as metal extraction, oxygen extraction, and metal oxide additive manufacturing processes. The apparatus uses a dual-strength magnet system with N52 and N42 neodymium magnets to separate particles by magnetic susceptibility. The electrostatic separation system, which acts like a sieve, sorts the regolith simulant by particle size using a single-phase 50% …

The Dynamics Of Near-Limit Detonation Waves For Hypersonic Propulsion, Liliana Berson

Graduate Studies Theses and Dissertations 2026

The usage of detonation waves in hypersonic propulsion engines has seen substantial advancement in recent decades. The near-limit transition and failure process are key in these applications controlling the operability regime. The common cellular propagation of detonation waves fails in the near limit leading eventually to a singular transverse shock instability. The local dynamics of the wave causing this transition and the details of this singular instability remain a challenging question. These dynamics are examined in a fully automated detonation experiment using ultra-high-speed diagnostics and statistical analysis. Hydrocarbon fuel–oxidizer mixtures with nitrogen dilution are used to explore transition behavior over …

An Algorithmic Framework For Polyhedral Gravity Modeling And Trajectory Propagation Near Small Bodies, Micah S. Boudreau

Graduate Studies Theses and Dissertations 2026

Near-Earth asteroids (NEAs) and other irregular celestial bodies have become increasingly significant targets for scientific investigation and space mission development due to their relevance to resource utilization, origins-of-life studies, planetary defense, and understanding of early solar system formation. As launch costs continue to decline, missions such as NASA’s NEAR Shoemaker, OSIRIS-REx and JAXA’s Hayabusa series demonstrate the expanding feasibility of detailed small body exploration. Despite this growing interest, most standard astrodynamics tools are not designed to model the complex, highly irregular gravitational fields that are a signature of small bodies. Such limitations pose challenges for trajectory design, navigation, and control …

Modeling And Testing Chain Trencher Excavator And Cone Penetrometer Robotic Prospecting Systems For Lunar In-Situ Resource Utilization, Marcello C. Guadagno

Dissertations, Master's Theses and Master's Reports

The Artemis Missions aim to establish a sustained human presence on the Moon, requiring In-Situ Resource Utilization (ISRU) of water-ice deposits in permanently shadowed regions. Two critical capabilities must be developed to enable ISRU at scale: prospecting instruments that can characterize the spatial distribution and geotechnical properties of icy regolith in situ, and excavation systems that can extract hardened icy regolith efficiently. This dissertation addresses both needs through the development and testing of a Percussive Heated Cone Penetrometer (PHCP) for geotechnical prospecting and a chain trencher excavator for icy regolith mining.

The PHCP was developed across eight design iterations and …