Aerospace Engineering Commons^™

Development Of Turbulence Models For Prediction Of Hypersonic Flows Using Compressibility Corrections And Uncertainty Quantification With Emphasis On The Wray-Agarwal Model, Aidan Robert Murphy

McKelvey School of Engineering Graduate Student Theses & Dissertations

Accurate prediction of high-speed compressible turbulent flows remains one of the most significant challenges in Computational Fluid Dynamics (CFD), especially in the realm of hypersonic vehicle design. These flow regimes involve significant aerodynamic heating and shock-wave boundary layer interactions (SBLI) which remain a significant challenge for the current CFD prediction capabilities. While Direct Numerical Simulation (DNS) and Large-Eddy Simulation (LES) provide high-fidelity solutions, their computational demands limit their usability, making the Reynolds-Averaged Navier-Stokes (RANS) equations an efficient alternative for many industrial aerodynamic applications. Traditional RANS techniques, while computationally efficient, often provide limited accuracy in high-speed flows due to the presence …

Development, Numerical Simulation, And Optimization Of Quiet Supersonic Transport Aircraft And Extension Of The Wray-Agarwal Algebraic Transition Model To Include Compressibility And Crossflow Effects, Dean Ryan-Simmons

McKelvey School of Engineering Graduate Student Theses & Dissertations

In the first part of this thesis, the goal of the research is to implement and extend multi fidelity methods for conceptual design and optimization of a commercial supersonic transport (SST). Most modern commercial aircraft operate at a cruise condition between Mach 0.7 and 0.9, as this is the optimal trade-off of flight efficiency, operational cost, and adherence of noise regulations for overland travel. Advancements in aviation propulsion fuel efficiency and design materials suggests a primary restraint on commercial supersonic transport is noise regulations. At speeds above Mach 1, the shock waves generated by the airframe are strong enough to …

Transition And Instability Characteristics Of The Separated Shear Layer Formed At Low Reynolds Number Over Three-Dimensional Irregular Rough Surface, Ganesh Kt Mr

Theses and Dissertations

The present experimental work investigates the effects of irregularly roughened surfaces and imposed streamwise pressure gradients on the topological, transitional, and instability characteristics of the laminar separated shear layer (SSL). Experiments are conducted in the low-speed wind tunnel for 𝑅𝑒𝑡=30000, based on the thickness of the airfoil model, t, and freestream turbulence intensity, fst = 0.8%. The airfoil model used in this study features a semicircular leading edge followed by a constant-thickness flat portion and a pitchable trailing-edge flap. Test conditions include two rough surfaces: sandblasted (SB) and sand-deposited (SD), and flap deflections: 𝛽=−30° and 𝛽=+30°, imposing adverse (APG) and …

Bio-Inspired Electroactive Polymer (Eap) Sensors For Surface And Canal Flow Sensing In Dynamic Environments, Nazanin Minaian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nature can often create some of the most efficient and elegant solutions to complex problems, and engineering stands to benefit greatly from these time-tested designs. One of the more sophisticated examples of this is the lateral line system in fish: a distributed network of superficial and canal neuromasts that enables aquatic species to detect fluid disturbances with remarkable precision. This dissertation leverages that biological framework to explore the potential of electroactive polymers (EAPs), aiming not just to replicate structure, but to emulate function.Two classes of EAPs form the basis of this work: electroactive plasticized polymer gels (EPPGs) and ionic polymer-metal …

Orbital Maneuvers And Interplanetary Trajectory Design Via Reinforcement Learning, Roberto Cuéllar Rangel

Doctoral Dissertations and Master's Theses

This dissertation investigates the application of reinforcement learning (RL) to the design and optimization of low-thrust spacecraft trajectories, with an emphasis on autonomy, adaptability, and robustness in the presence of system uncertainties and unmodeled perturbations. Classical approaches to low-thrust trajectory design are predominantly grounded in optimal control theory, which relies on the availability of precise dynamical models and often requires problem-specific reformulation and solver tuning. While optimal control methods offer high accuracy under deterministic conditions, their sensitivity to stochastic disturbances and computational limitations in highly nonlinear or uncertain environments pose significant challenges for future autonomous space missions.

To address these …

Life And Performance Improvement Trenches, Thomas J. Praisner, John R. Farris, Connor Wiese

AFIT Patents

A blade outer air seal assembly includes a plurality of seal segments circumferentially disposed about an array of blades rotatable about an axis, each of the plurality of seal segments having a radially inner surface facing a tip of each blade of the array of blades, the radially inner surface having an arrangement of trenches formed therein, and a radially outer surface opposite the radially inner surface. The arrangement of trenches is disposed between 30% and 80% of a chord of a blade of the array of blades as taken at the respective tip, and the arrangement of trenches is …

Satellite Passive Ranging Metasurface Optics For Space Rendezvous And Proximity Operations, Zachary Coppens, Cameron Vo, Addison Long, Jeremy Harris

Space Dynamics Laboratory Publications

SDL Presentation on Satellite Passive Ranging Metasurface Optics for Space Rendezvous and Proximity Operations

An Inexpensive, Open, And Extensible Hardware-In-The-Loop Cubesat Test And Simulation Infrastructure, Andrew Greenberg, Glenn Lebrasseur, Max Eltzroth, Rose Edington, Anna Meneely, Maxwell Millar

Small Satellite Conference

We have developed an inexpensive, open source, and extensible hardware-in-the-loop (HIL) test and simulation system to allow even small CubeSat teams to dramatically improve their testing infrastructure to increase reliability during flight.

Design Of A Fan-Based Test Stand For Evaluating Multicopter Handling In Turbulent Flow, Salim Roig

Doctoral Dissertations and Master's Theses

With the innovation of eVTOL rotorcraft the need to analyze how turbulence-induced disturbances from orthogonal flow affect various rotorcraft configurations outside of simulations have grown significantly. To investigate the behavior of this type of flow and how it interacts with various rotorcraft configurations, a turbulent inducing test stand was designed and constructed. The test stand will have two walls of computer fans arranged in an L-shape frame, creating wind gusts that simulate the non-linear turbulent wind experienced by eVTOL. This also aids the Eagle Flight Research Center (EFRC) in their efforts to better understand how disturbances affect the handling qualities …

Calibration And Validation Of The Thermal Finite Element Model For Er120s-G Wire Arc Directed Energy Deposition Using Infrared Cameras And Thermocouples, Joshua Mykl Bassett

Theses and Dissertations

Wire Arc Directed Energy Deposition (WA-DED) is a promising additive manufacturing method for producing large metallic components with high deposition rates and low costs. However, its rapid heat input can lead to residual stress, microstructural changes, and dimensional inaccuracies. Accurate thermal modeling is essential to mitigate these effects. This study presents a thermal calibration of a finite element model (FEM) for ER120S-G using thermocouples and infrared (IR) imaging. Thermal data were gathered from three experiments to complete the calibration of the FEM . Calibration focused on tuning the Goldak heat source parameters, power efficiency, and heat transfer coefficients to minimize …

Opto-Mechanical Properties Of Monocrystalline Germanium, Phil Scott, Lennon Reinhart, Patrick Strong, Ryan Luder, Shayler Backlund, Trent Newswander

Space Dynamics Laboratory Publications

SDL Presentation on Opto-Mechanical Properties of Monocrystalline Germanium

Atmospheric Waves Experiment (Awe) Thermal Balance: Internal Characterization, Correlation, And Lessons Learned, Matt Ralphs, Mike Holt

Space Dynamics Laboratory Publications

The Atmospheric Waves Experiment (AWE) is providing the first global characterization of atmospheric waves that originate in Earth’s lower atmosphere and affect space weather. The instrument has been installed on the International Space Station’s (ISS) ExPRESS Logistics Carrier (ELC) site 1 since November 2023. The AWE flight thermal balance test at Space Dynamics Laboratory (SDL) was unique in that the radiation exchange from the radiators was not tested prior to flight. Instead, heaters were placed on the radiators to simulate environmental heat and control the boundary temperatures. Multi-layer insulation (MLI) was installed over the radiators and heat flow meters were …

Impact Of Uncertainties On Structures Damage Tolerance Parameters, Breno De Bruns

Doctoral Dissertations and Master's Theses

This research aims to enhance the understanding and management of aerospace structural integrity. Traditional fracture control methods, such as damage tolerance analysis (DTA), assume deterministic factors, considering uncertainties inherent in material properties, inspections, and operational conditions only at the final stage by applying safety factors. This research seeks to incorporate these uncertainties throughout the analysis by integrating Monte Carlo simulation with Linear Elastic Fracture Mechanics (LEFM). The objective is to investigate how varying parameters affect crack growth prediction and the effectiveness of inspection strategies. The methodology involves systematically analyzing inspection intervals, considering factors like material properties, probability of detection (POD), …

High-Heat Transfer Lithium-Ion Batteries: A New Era In Battery Thermal Management, Alfred J. Piggott, Jeffrey S. Allen, Ahmad A. Pesaran

Michigan Tech Publications

Despite advances in lithium-ion battery technology, critical challenges remain that must be addressed to accelerate electric vehicle (EV) adoption and global energy transformation. Significantly improved battery thermal management (BTM) is key to overcoming these challenges. BTM approaches focus on increasing heat transfer coefficients via air, liquid, or refrigerant cooling, but less attention is given to reducing the battery's thermal resistance, a major bottleneck for heat transfer. This work introduces a novel approach to reduce battery thermal resistance by integrating in-plane heat transfer with optimized cell geometry, minimized thermal resistances, and reduced interfacial resistances, representing a departure from previous methods. The …

Mae Enewsbrief Apr- June 2025, Department Of Mechanical And Aerospace Engineering, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Mission-To-Designs: Automating Uav Conceptual Design Generation, Nana A. Adjei

All Theses

The conceptual design stage of Unmanned Aerial Vehicles (UAVs) is an exploratory phase where designers are tasked with developing and evaluating a wide range of viable design concepts, considering different geometries and configurations based on mission requirements. The goal is to identify the most suitable design after the exploration for further development and progression to the next phase. Several tools and frameworks have been developed to assist designers in this stage, each offering unique capabilities, but all with the common aim of aiding in the efficient development and evaluation of conceptual designs. This is important in the UAV design process …

Robust Adaptive Rigid Body State And Mass Property Estimation Via Unscented Kalman Filter On Tse(3) With Process Noise Estimation, Herman Gunter

Doctoral Dissertations and Master's Theses

Mass property estimation, including mass, center of mass, and moment of inertia, is a crucial yet challenging problem in spacecraft autonomy and astrodynamics. Knowledge of mass properties of a spacecraft is essential for future astronautical missions, as changes in the mass properties of a spacecraft due to a shift in cargo distribution often require a careful and costly recalculation to ensure applied control inputs produce the desired results. As spacecraft missions grow in both duration and number, meeting the need for precise and accurate measurements becomes increasingly complex. Stochastic effects, such as angle and velocity random walks, along with persistent …

Real-Time Fiducial Marker Based Localization For Autonomous Unmanned Aerial Vehicle Navigation, Sourav Raxit

LSU New Orleans Theses and Dissertations

By harnessing fiducial markers as visual landmarks in the environment, Unmanned Aerial Vehicles (UAVs) can rapidly build precise maps and navigate spaces safely and efficiently, unlocking their potential for fluent collaboration and coexistence with humans. Existing fiducial marker methods rely on handcrafted feature extraction, which sacrifices accuracy. On the other hand, some deep learning pipelines for marker detection fail to meet real-time runtime constraints crucial for navigation applications. In this work, I propose YoloTag- a real-time fiducial marker-based localization system. YoloTag uses a lightweight YOLO v8 object detector to accurately detect fiducial markers in images while meeting the runtime constraints …

Model-Based Systems Engineering For Aerospace Applications: Strategic Requirements Prioritization In Complex Adaptive Systems And Digital Integration, Iqtiar Md Siddique

Open Access Theses & Dissertations

Ineffective systems engineering practices continue to jeopardize aerospace missions, resulting in multi-billion-dollar losses, delays, and fragmented development outcomes. As complexity intensifies and timelines shrink, conventional document-based methods increasingly fail to support early validation, cross-domain traceability, and synchronized tool usage. This research presents an integrated approach that addresses three critical gaps: synchronizing executable and traceable MBSE models across structural, behavioral, and requirements domains; applying scalable requirements prioritization techniques tailored for Complex Adaptive Systems; and establishing automated simulation feedback loops through digital toolchain integration. Central to this strategy is the Digital Trinity, which connects system models, simulations, and lifecycle data through a …

Linearized Rigid-Body Dynamics Of Asymmetric Aircraft, Troy A. Abraham

All Graduate Theses and Dissertations, Fall 2023 to Present

Most aircraft are symmetric about their mid-plane, which permits simplifying assumptions when modeling their aerodynamic and mass properties, as well as estimating their dynamic modes. This work considers methods for modeling asymmetric aircraft, including capturing the dynamic mode characteristics that result from their asymmetric properties. While the primary focus of this work is on the dynamic mode properties of these aircraft, a significant portion of the dissertation is dedicated to modeling their aerodynamic, mass, and trimmed flight characteristics. The linearized rigid-body aircraft equations of motion used for dynamic mode estimates are developed to include the effects of asymmetries in both …

Evaluating The Impact Of Maximum Aero-Thermal Heating On A High-Speed Fixed-Wing Atmospheric Aircraft Optimum Trajectory, Benjamin M. Ford

All Graduate Theses and Dissertations, Fall 2023 to Present

This study explores how extreme heating affects the flight paths of hypersonic aircraft—vehicles that travel at speeds many times faster than sound. Analyzing how to fly a high-speed aircraft without overheating it can prevent structural failure while operating at maximum possible performance. The results shown in this section indicate that it is possible to operate at very high speeds in an aircraft while keeping peak vehicle temperature below our limits while saving fuel.

Development And Application Of Novel Apparatus For Ocean Spray In Turbulent Atmospheres, Alicyn S. Koldewyn

All Graduate Reports and Creative Projects, Fall 2023 to Present

Ocean spray droplets can have significant effects including reducing surface heating from the sun, degrading air quality, and intensifying tropical cyclones. However, quantifying these effects has been challenging due to the multiscale, chaotic nature of wave breaking and turbulent flow. This research presents the development of a novel apparatus designed to combine bubble column droplet generation with synthetic jet actuators for turbulence generation. The purpose is to demonstrate reliable bubble formation and droplet generation, air turbulence effect on droplet dynamics, and quantitative measurement and analysis of these effects. The primary goals of the apparatus include optical accessibility for high-resolution imaging, …

3d Printing Of Short Fiber Reinforced Polypropylene: Novel Lattice Architecture And Material Characterization, Mohammad Ghazi Alshneeqat

Theses

This study explores the enhanced compressive behavior of 3D-printed single and double gyroid solid-networks lattices. Where the double gyroids are constructed from two intertwined single gyroid structures. These structures were designed by nTop implicit modeling tool and then fabricated by material extrusion additive manufacturing method at optimized printing parameters, including optimized nozzle temperature and raster angle. The main objective of this study is to reveal the compressive behavior of the novel double gyroid lattice structure and then to tailor its response through variable gyroid heights. Standard polymer tests were performed, considering thermogravimetric analysis, to confirm the thermal stability of the …

Advancing Life Cycle Assessment For Environmental Sustainability Of Carbon Fiber-Reinforced Polymer Composites (Cfrps)), Hao Chen

All Dissertations

Carbon fiber-reinforced polymer composites (CFRPs) have emerged as promising materials, particularly for lightweight applications, with the potential to reduce environmental impacts across multiple sectors, including automotive, aerospace, and renewable energy. However, fully realizing their sustainability potential requires a more comprehensive and context-specific understanding of their environmental performance throughout the entire life cycle—from raw material production to end-of-life management.

This dissertation advances life cycle assessment (LCA) practices for CFRPs by addressing key challenges across multiple phases of the CFRP life cycle. First, I conducted a critical review and meta-analysis of carbon fiber manufacturing, revealing substantial variability in reported data on energy …

Analysis On Plasma Propulsion Thruster Material Reconfiguration For Thrust Stabilization, Chinedumu Chidiebere Okafo

Mechanical & Aerospace Engineering Theses & Dissertations

Rocket propulsion has been a primary focus for scientific and technical advancement supporting space exploration. For long-duration, low-thrust space missions, propulsion systems designed with plasma energy as the primary source for generating thrust are of high interest. Plasma energy, like electric propulsion, involves the excited state of ionized atoms, where the ionized particles are separated and then act as a propellant to push a spacecraft in the intended direction for flight. Although more energy efficient compared to traditional rocket systems, plasma propulsion has the deficiency of consistent erosion of the metallic containment substrate, as plasma is being generated and released …

Advancing Real-World Implementation Of The Well Optimized Linear Finder (Wolf) High-Speed Atmospheric Turbulence Compensation Method, Timothy Evan Coon

Theses and Dissertations

This dissertation advances the real-world implementation of the Well Optimized Linear Finder (WOLF) method for high-speed Atmospheric Turbulence Compensation (ATC). Atmospheric turbulence introduces phase aberrations into optical wavefronts and degrades image quality in terrestrial imaging systems. Traditional phase diversity methods are computationally intensive and poorly suited to real-time operation. The WOLF method addresses these limitations through a novel, point-wise formulation of the optical transfer function (OTF) as a structured autocorrelation of the generalized pupil function (GPF). This formulation enables the estimation of phase aberrations at individual spatial coordinates with distributed computational complexity.

The research begins by developing a MATLAB-based simulation …

Shock Induced Droplet Aerobreakup For Newtonian And Non-Newtonian Fluids, James Leung

LSU Doctoral Dissertations

This research investigates shock-induced aerodynamic breakup (aerobreakup) of fluids with different stress-strain behaviors. The central hypothesis is that shear stress from highspeed gas flow manifests differently depending on a fluid’s strain response, influencing droplet breakup morphology, fragment size distribution, and drag-induced acceleration. To test this, experiments and simulations were performed on μm–mm sized droplets of Newtonian (water) and shear-thinning fluids (nanofluids or xanthan gum). Two experimental setups were used: an open-ended shock tube and a closed conventional shock tube. In the openended setup, a normal shock impacts a stationary droplet held by an acoustic levitator. Droplet breakup and gas dynamics …

Flysurf: A Flying Robotic Surface With Shape Morphing And Motion Control, Kevin Aubert De Luchi Lomellini

Electrical and Computer Engineering ETDs

This thesis introduces FlySurf, a novel flying robotic surface capable of simultaneous shape morphing and motion control. FlySurf is modeled as a mesh-based dynamic structure actuated by multiple unmanned aerial vehicles, enabling complex deformations during flight. The proposed control architecture comprises three main components. First, a state estimator to infer the robotic surface state from limited observations. Second, a shape trajectory planner that incorporates an affine deformation term to preserve surface integrity during shape transitions. Third, a surface controller to minimize the error between the desired and actual surface configurations.

The methodology is validated through realistic simulations and hardware experiments, …

Design For Additive Manufacturing: Simultaneous Optimization Of Structural Integrity And Minimal Support Structures, Naresh Ahuja

Doctoral Dissertations and Master's Theses

This dissertation addresses two core challenges limiting the widespread application of Topology Optimization (TO): the difficulty in fabricating its complex designs, especially for Additive Manufacturing (AM), and its significant computational costs. It develops a unified design framework that directly embeds AM constraints such as overhang angles and build direction into robust TO formulations. To enhance manufacturability, two distinct methodologies are proposed. Firstly, a Solid Isotropic Material with Penalization (SIMP) framework introduces a three-stage robust optimization algorithm. Secondly, the Geometric Projection Topology Optimization (GPTO) method inherently integrates overhang constraints by controlling individual geometric components and their inclined angles relative to a …

Implementing A 5-Dimensional Tabulated Conditional Moment Closure Model With Scalar Dissipation Rate For Scramjet Combustion, Alp Tuztas, Scott Montgomery Martin, Carlos A. Velez

Discovery Day - Daytona Beach

The growing interest in Scramjets for achieving sustained hypersonic flight has given rise to numerous computational models to obtain solutions as close as possible to experimental data, assisting with making the design process of modern Scramjet’s with different propellants and cavity designs less costly. However, Scramjet engines pose significant challenges for computational modelling due to the need of accounting for large- and small-scale turbulences but also solving turbulence chemistry interactions in compressible flow regimes. A promising approach has been through using high-fidelity turbulence-combustion models which greatly assist with capturing detailed chemistry, account for small scale turbulence and the complex flow …