Mechanical Engineering Commons^™

Experimental Rate Feedback Control Of A Model-Scale Hourglass-Shaped Heaving Point Absorber, James R. Halverson

Dissertations, Master's Theses and Master's Reports

Buoy geometry greatly affects a point absorber wave energy converter's dynamic response to waves. Finding the optimal buoy shape and control method remains an open research area focused on maximizing the conversion of wave kinetic energy into electricity. This work presents an experimental comparison of closed-loop energy extraction between a cylindrical and a truncated cone buoy, both with the same submerged volume, across various wave frequencies and amplitudes. To ensure a fair comparison, the optimal rate feedback gain is calculated for each buoy at each wave condition. Multiple metrics, including power output, capture width, and actuator force, are used to …

Nondestructive Evaluation Of Additively Manufactured Parts Using Resonant Inspection And Frequency Domain-Based Correlation Criteria, Gita Deonarain

Dissertations, Master's Theses and Master's Reports

Additive manufacturing (AM) enables the production of highly customized and geometrically complex components; however, these parts remain susceptible to a wide range of defect types and severities. The combination of complex geometries and distributed defects presents a significant challenge for post-process nondestructive evaluation (NDE). Conventional inspection techniques, such as computed tomography and ultrasonic testing, are often limited by geometry, material, accessibility, and cost, while in situ monitoring is not yet sufficiently mature to replace post-process inspection.

This dissertation establishes the Frequency Domain Assurance Criterion (FDAC) as a quantitative, vibration-based framework for defect detection in AM components. FDAC captures spatial–spectral correlations …

Microgravity-Induced Alterations In Left Atrial Hemodynamics And Thrombogenic Risk: Insights From Healthy And Atrial Fibrillation Models, Grace M. Hoeppner

Dissertations, Master's Theses and Master's Reports

Background: Microgravity exposure alters cardiovascular loading, yet its impact on left atrial flow dynamics and thrombotic risk remains poorly understood. This study investigates how spaceflight-relevant microgravity-induced changes in cardiac outflow affect left atrial hemodynamics in healthy individuals and patients with atrial fibrillation.

Methods: Patient-specific left atrial models were generated for three healthy individuals and three AF patients. Computational fluid dynamics (CFD) simulations were performed using each patient’s baseline mitral outflow waveform and two modified waveforms representing short- and long-duration post-flight cardiac loading changes derived from echocardiographic observations. Hemodynamic metrics included left atrial velocity, time averaged wall shear stress, oscillatory shear …

Development And Calibration Of A 2-D Diesel Oxidation Catalyst Filter (Docf) Model With Spatially Varying Washcoats Using Spacims And Engine Loading Data, Thomas K. Price

Dissertations, Master's Theses and Master's Reports

Diesel engine exhaust contains regulated species, including carbon monoxide, hydrocarbons, nitrogen oxides, and particulate matter (PM). Meeting increasingly stringent emission standards typically requires multiple aftertreatment components, motivating the development of multifunctional devices that reduce system size, cost, and catalyst usage. Computational models are essential for guiding this design process; however, existing models primarily focus on single-function devices and rarely capture the behavior of multifunctional systems with multiple catalyst washcoats. This work presents a physics-based model of a wall-flow diesel oxidation catalyst filter (DOCF), a multifunctional device that integrates the roles of a diesel oxidation catalyst and a diesel particulate filter …

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 …

Machine Learning And Multi-Scale Optimization For Control And Energy Management In Connected And Automated Vehicle Propulsion Systems, Joshua D. Orlando

Dissertations, Master's Theses and Master's Reports

This dissertation presents a multi-scale optimization framework leveraging machine learning (ML) to enhance energy efficiency in connected and automated vehicle (CAV) propulsion systems. As transportation transitions toward hybridization and automation, the integration of vehicle-to-everything (V2X) connectivity and advanced control algorithms offers unprecedented opportunities for energy reduction. This research addresses three critical scales of vehicle energy management: multiple vehicle-level coordination, component-level powertrain dynamics, and real-time vehicle parameter estimation.

First, the research investigates the energy consumption characteristics of heterogeneous propulsion systems—ranging from internal combustion engines to battery electric vehicles across light- and heavy-duty sectors—on arterial roadways. Utilizing Particle Swarm Optimization (PSO) and …

Study Of Bearing Capacity Testing And Soil Preparation Techniques In Lunar Highlands Simulant At Field Scale, Christi A. Lecaptain

Dissertations, Master's Theses and Master's Reports

Humanity seeks to return to the surface of the Moon with the advent of the Artemis missions. These endeavors plan to be the beginning of a new era as NASA and other space organizations seek to establish a lunar base. Ahead of any astronauts or mining infrastructure, the physical groundwork will need to be laid to support the arrival of rockets, boots, and rover wheels. As surfaces are prepared, they will need to be tested and verified to ensure the stability of any structures placed on top. Understanding the bearing capacity is vital to soil quality testing. A standard terrestrial …

Design And Experimental Evaluation Of A Custom Vision-Guided Approach To 2d Part Localization For Industrial Robots, Faisal Ali

Dissertations, Master's Theses and Master's Reports

Vision-guided robots offer a clear advantage over teach-pendant programming for battery handling, where modern packs hold thousands of cells and teaching each position by hand does not scale. Commercial vision systems address this need, but their calibration, detection, and coordinate-conversion stages are closed to the user, making it hard to incorporate newer learning-based methods. This work presents a modular, custom-built vision-guided system using an Orbbec Gemini 435Le eye-in-hand camera, an NVIDIA Jetson Orin Nano, an Allen-Bradley Micro850 PLC, and a FANUC LR Mate 200iC, communicating over Modbus TCP and EtherNet/IP. A per-hole classification model resolves each known hole into a …

Analytical And Data-Driven Modeling And Control Of Nonlinear Point Absorber Wave Energy Converters With Application To Cone–Cone Buoy Geometries, Houssein Yassin

Dissertations, Master's Theses and Master's Reports

This dissertation develops analytical modeling, numerical simulation, experimental validation, and data driven control methods for nonlinear point absorber wave energy converters, with particular emphasis on cone--cone buoy geometries. Geometry dependent nonlinear force models are first derived using pressure field and displaced volume formulations. These models show how buoy geometry produces nonlinear Froude--Krylov and restoring forces, including the dominant cubic behavior of cone--cone geometries.

The derived models are incorporated into a feedback linearization framework that compensates selected nonlinear dynamics while retaining the incident wave terms. An analytical optimal control formulation is also developed to maximize harvested energy in nonlinear, nonautonomous systems …

Performance Comparison Of A Low Mass Vibratory Lunar Surface Compactor In Vacuum Versus Atmosphere, Robin D. Austerberry

Dissertations, Master's Theses and Master's Reports

As space agencies prepare to return to the moon, an emphasis is being placed on establishing a sustained human presence that requires permanent structures and supporting infrastructure, making site preparation a critical factor. Michigan Technological University’s Planetary Surface Technology Development Lab has developed a novel low-mass surface compaction tool for use on a site preparation vehicle in collaboration with Colorado School of Mines. Testing in vacuum is necessary to simulate a relevant environment, which is required to increase the technology readiness level of this tool to TRL 5. Testing concluded significant interactions between the presence of atmosphere and other factors. …

Minimizing Snow Loss On Fixed Tilt Solar Pv Installations Through Frame Material Selection And Installation Layout, David B. Wallis

Dissertations, Master's Theses and Master's Reports

This thesis investigates the effects of frame material selection, module orientation and module gaps on photovoltaic energy production in a snowy environment. These factors are easily implemented in new PV installations at minimal or no extra cost. These experiments are installed as fixed tilt arrays at 35° with DC current, DC voltage, and meteorological monitoring. The frame material and module gap experiments both produced actionable results. In the frame material experiment, consistent event level energy production gains resulted in seasonal production gains favoring aluminum framed modules. In the module gap experiment energy gains are independent of atmospheric conditions. The orientation …

Adaptive Machine Learning Framework For Microstructural Optimization And Mechanical Performance Prediction In Steels, Henry Adekola Haffner

Doctoral Dissertations

Evolution of microstructures, such as polygonal ferrite, acicular ferrite, bainite, and martensite, plays a pivotal role in determining the final microstructural and mechanical properties of steel products. Given the established inter-relationship between processing parameters, microstructure, properties, and performance, precise control of phase transformation is essential to achieve pre-determined properties. To understand transformation routes in different steel grades, time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams are necessary and can be described using the Johnson-Mehl-Avrami-Kolmogorov equation and Scheil’s additivity rule. This study presents a comprehensive computational framework for predicting and optimizing microstructure and mechanical properties in advanced high-strength steels (AHSS) using adaptive machine …

Fabrication And Characterization Of A High Strength Novel Aluminum Alloy For Implementation With Directed Energy Deposition, Rachel Boillat-Newport

Doctoral Dissertations

"Additive manufacturing (AM) is of significant interest due to the ability to fabricate 3D components layer-by-layer. Compared with traditional manufacturing methods, AM allows for the direct fabrication of complex, intricate parts without the need for extensive machining, reducing manufacturing time and tooling costs and minimizing material waste. Aluminum alloys are highly desired for implementation via AM due to their high strength-to-weight ratios; however, there are several challenges that complicate the situation and hinder the use of aluminum alloys. One of the most challenging issues is that the desired high-strength alloys are not compatible with AM processing methods. A method to …

Critical Parameters Controlling Oxide Scale Formation And Hydro-Descaling Efficiency During Steelmaking, Tochukwu Princewill Ojiako

Doctoral Dissertations

In modern steelmaking, cast slabs are exposed to high-temperature oxidizing environments during secondary cooling, reheating, and hot rolling, resulting in the formation of multilayer oxide scales on the steel surface. These scales interact with mold-flux residues originating from the casting process (CC). The morphology, chemistry, and adhesion of oxide scale strongly influence its removability during high-pressure hydraulic descaling and ultimately determine the surface quality of hot-rolled products. However, the mechanistic relationship between oxide scale evolution, scale-steel interfacial structure, and hydraulic descaling performance remains poorly understood.

This dissertation investigates oxide scale formation, modification, and removal in low-carbon thin-slab steels produced by …

Influence Of Surface Features On Heat Transfer During Dropwise Condensation Over Superhydrophobic Surfaces In Shear Flow, Shaur Humayun, R. Daniel Maynes, Julie Crocket, Brian D. Iverson

Faculty Publications

This study investigates heat transfer during dropwise condensation (DWC) on superhydrophobic (SH) surfaces in humid air shear flow, emphasizing the effect of increased drop mobility and the influence of surface micro/nanostructure on heat transfer rates. Experiments were conducted on smooth hydrophobic, microstructured SH, nanostructured carbon-infiltrated carbon nanotube (CICNT) surfaces, and two-tiered SH surfaces with both micro and nanostructures. Heat transfer rates were measured under humid air flow rates in the range of 2–4 CFM. Experimental results demonstrate that surfaces with nanostructure (including two-tiered structures) exhibit increased drop mobility and coalescence-induced drop jumping, enhancing drop removal rates and overall heat transfer …

Efficiently Stowed Flashers With Uniform-Thickness Panels Based On Non-Developable Origami, Larry L. Howell, Robert J. Lang, Specer P. Magleby, Davis Wing

Faculty Publications

We present the mathematical construction of a deployable flasher pattern with near-uniform nonzero thickness in the deployed form and efficient face-to-face packing in the stowed form. We demonstrate its fabrication, deployment, and stowage. The results facilitate the design and manufacture of deployable systems with panels whose substantial thickness is dictated by the end application, with particular utility for space systems.

The Efficacy Of Hybrid Manufacturing For High Stress Automotive Parts, Logan Trimmer

Harrisburg University Other Works

Presentation covering the broad strokes of the project. The goal was to prove the viability of hybrid/additive manufacturing for high stress automotive applications. This project focused on recreating a piston from an old engine to examine if hybrid manufacturing could be used for such applications. On a small scale, hybrid manufacturing was able to be more cost effective if the costs of the equipment and electricity were ignored. The decision to ignore those costs came from the inability to find accurate prices for industrial casting.

Automation And Habitat Development For A Space Based Marine Life Environment, Logan Trimmer, Alexander Hang

Harrisburg University Other Works

This project was a cross-collaboration between the Environmental Sciences and Advanced Manufacturing and Robotics programs for the company Monolith Space.

The goal of this project was to design an autonomous system to be able to track qualities of water in an aquaculture system designed to be sent to space.

The Efficacy Of Hybrid Manufacturing For High Stress Automotive Components, Logan Trimmer

Harrisburg University Other Works

The goal of this research was to establish the viability of using hybrid manufacturing for automotive applications. By verifying that high-stress components can be created, it can be assumed that any other lower stress part could be made to match the strength requirements. A limiting factor of adoption for hybrid manufacturing is how new the technology is. Studies on time and cost were performed allowing for comparisons with traditional manufacturing technologies (casting, forging, milling) used in automotive applications. This research utilized a Haas Automation UMC750 5-axis CNC mill with a Meltio laser wire direct energy deposition attachment. Fusion 360 was …

Machine Learning For Predictive Energy And Emissions Modeling Of Vehicles And Power Grids In The United States, S M Tanvir Faysal Alam Chowdhoury

Dissertations

The environmental benefits of electric vehicle (EV) adoption depend on more than replacing internal combustion engine vehicles with electric powertrains. EV adoption reshapes electricity demand, interacts with regional generation mixes, and influences travel behavior and congestion, creating a coupled transportation-energy system in which vehicle and power-plant emissions must be evaluated together. This dissertation develops machine-learning frameworks for predicting energy consumption and emissions from vehicles and power grids under rising EV adoption. The first component forecasts grid emissions from EV charging. Using simulation data from NREL's Cambium database, a Prophet-based time-series framework predicts carbon dioxide, nitrous oxide, and methane emission rates …