Engineering Commons^™

Characterization Of Cooled Turbine Efficiency For Off-Design Performance Models, Alberto Garcia

Doctoral Dissertations and Master's Theses

Gas turbine performance modeling is essential for predicting engine behavior across design and off-design conditions. Yet the treatment of cooling or service flows remains inconsistent, as these streams interact with the main flow in complex ways and their contribution to turbine work depends on how they are represented in performance models. The challenge is especially present in “black-box” approaches, where only inlet and outlet conditions are known and engineers must decide whether to introduce cooling flows upstream (if performing useful work) or downstream (if not). This thesis examines how different definitions of isentropic power and cooling-flow treatment affect the apparent …

Characterization Of The Fatigue Threshold Behavior Of Uhmwpe, Bethany B. Smith, Anurag Roy, Robert O. Ritchie, Lisa A. Pruitt

Faculty Journal Articles

Ultra-high-molecular-weight-polyethylene (UHMWPE) has been the material of choice for bearings in total joint replacements (TJRs) for decades as a result of its excellent wear resistance, chemical inertness, energetic toughness, low friction, and biocompatibility. Utilization of this polymer in orthopedic devices requires oxidation, wear, and fatigue resistance. Balancing these important properties by tailoring processing techniques and modulating microstructural features has been an ongoing endeavor in the field. Research into the clinical applications of UHMWPE has primarily focused on the challenges of wear and oxidation while studies into the realm of fatigue have been more limited. Literature gaps exist in fully understanding …

High-Fidelity Modeling Of Evtol Rotor Unsteady Aerodynamic And Aeroacoustic Response To Time-Harmonic Gust, Vadim Voropayev

Doctoral Dissertations and Master's Theses

The rapid emergence of Urban Air Mobility (UAM) demands accurate prediction and mitigation of noise generated by electric vertical take-off and landing (eVTOL) aircraft operating in complex urban environments. Among the various noise sources, the aerodynamic and acoustic response of rotors to unsteady inflow represents a major uncertainty in community-noise assessment and certification. This thesis investigates the aerodynamic and aeroacoustic behavior of a representative eVTOL rotor subjected to time-harmonic inflow disturbances, providing a detailed numerical framework to quantify how periodic gusts influence rotor performance, unsteady loading, and sound radiation.

The study employs a three-stage computational methodology using the open-source solver …

Integration Of Sco2 Brayton Cycles With Carbon Capture Systems, Nathan C. Stearns, Rajarshi Roy, Brian Schooff, Andrew Chiodo, Andrew R. Fry, Brian D. Iverson

Faculty Publications

Increasing global energy consumption and greater market penetration of intermittent energy sources require a baseline power source to enable renewable energies. Here, a case is made for pairing supercritical CO₂ Brayton cycles with carbon capture to create low-emission, high-efficiency, combustion-based power generation systems. Pairing carbon capture and storage (CCS) systems with supercritical carbon dioxide (sCO₂) Brayton cycles enables the reduction of greenhouse gas emissions in combustion systems, but with an associated energy cost. Three different representative models of CCS systems (oxyfuel combustion, amine scrubbing, and cryogenic carbon capture) are considered for pairing with an sCO2 Brayton cycle, …

Internal Resonance Of A T-Shaped Electrostatic Levitation Actuator, Ali Eskandari, Mohammad Alzgool, Yu Tian, Mohammad I. Younis, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This study explores the internal resonance of a T-shaped beam subjected to electrostatic forces at the MEMS scale. The actuator's unique configuration includes a side substrate, a fixed bottom substrate, and a suspended beam, enabling out-of-plane movement when excited. The T-shaped beam is designed to have a commensurate ratio of 1:2 between the fifth and sixth modes. The mathematical model of the system is developed and the shooting method is used to solve the reduced order model. Theoretical and experimental results reveal the interaction of two modes. The results indicate that due to the exchange of energy between the two …

On Modeling Of Multiplicative Bias Factor For Multivariate Degradation Data, Bingxin Yan, Qiuzhuang Sun, Zhisheng Ye

Research Collection College of Integrative Studies

Multivariate degradation data are increasingly common due to advances in sensor technology. They provide rich information for reliability analysis and remaining useful life (RUL) prediction. The multivariate measurement typically contains actual degradation of multiple performance characteristics (PCs) and measurement errors. The multiple PCs often have different physical meanings with different orders of magnitude, making the associated measurement errors vary in the orders of magnitude as well. It is highly desirable to have a parsimonious model accounting for the possible correlation in degradation measurements, so that more flexibility can be reserved for modeling the actual multivariate degradation. This study proposes a …

Make Yourself Comfortable: Nudging Urban Heat And Noise Mitigation With Smartwatch-Based Just-In-Time Adaptive Interventions (Jitai), Clayton Miller, Xuan Yun Chua, Matias Quintana, Binyu Lei, Filip Biljecki, Mario Frei

Research Collection College of Integrative Studies

Humans can play a more active role in improving their comfort in the built environment if given the right information at the right place and time. This paper outlines the use of Just-in-Time Adaptive Interventions (JITAI) implemented in the context of the built environment to provide information that helps humans minimize the impact of heat and noise on their daily lives. This framework is based on the open-source Cozie iOS smartwatch platform. It includes data collection through micro-surveys and intervention messages triggered by environmental, contextual, and personal history conditions. An eight-month deployment of the method was completed in Singapore with …

Mems 4110: Asme Waste Collection Challenge, Evelyn Madrigal, Letty Patino, Bing Ling, Michael Avaliani

Mechanical Engineering Design Project Class

Make a remote-controlled vehicle that can traverse the course below (obeying traffic laws), collect garbage units from collection bins and deliver the garbage units to a receptacle.

Mems 4110: N1 Precise Water Distribution System, Lillian Salter, Ye Huang, Elaine Wang, Joy Luo

Mechanical Engineering Design Project Class

The aim of the project is to construct a precise water distribution system for anthropology graduate student Christina Youngpeter, who is studying the impact of hydration levels on the growth of quinoa plants. As her experiment grows in scale, she increasingly needs a system that can measure and distribute water for her, saving hours otherwise spent meticulously measuring water for 36 plants and counting. The system must measure water accurately and distribute it to the plants cleanly and efficiently. It should also be scalable and autonomous, requiring minimal human intervention.

Mems 4110: Asme Waste Collection Challenge, Theo A. Mass, Grant Kaplan, Emanoeel Ghabrial, Joseph Gillett

Mechanical Engineering Design Project Class

The Efficient Jolley Trash Grabber (EJTG) is a teleoperated vehicle adherent to the modified rules of the 2025-26 ASME Student Design Competition, hosted in MEMS 4110: Mechanical Engineering Design Project. The vehicle design was informed first by understanding the problem of waste collection. Patents, existing devices, user needs, and relevant codes and standards were reviewed to survey potential design approaches. The concept for the vehicle was generated by setting functionality, and brainstorming solutions to accomplish each goal. A mock-up vehicle was created using available materials, and four complete concepts were drawn each with a different design. Rigorous methods were used …

Mems 4110: Conservation Of Angular Momentum Demo, Matthew Brouillet, Iyanu Akinyemi, Mingxuan Bi, Matthew Gimbel

Mechanical Engineering Design Project Class

A demo was built to serve as a hands-on experience for reinforcing concepts behind the conservation of angular momentum.

Mems 4110: Parachute Snatch Force Tester, Adam Mallalieu, Ethan Riak, Jackson Shurman, Ryan Schmadtke

Mechanical Engineering Design Project Class

This report discusses the design, development, and testing of a parachute snatch force tester for MEMS 411 Senior Design. The device is for the WURocketry Team, and aims to measure the peak force exerted on the rocket bulkhead during parachute ejection. This peak force is known as the snatch force, and is incredibly important when it comes to maintaining safety, improving performance, and material selection during the rocket’s production process. Current methods for testing and recording this snatch force are limited, so our team aimed to create a simple and cost effective solution. Our design utilizes a vertical support that …

Mems 4110: Asme Challenge, Jon Cossman, Jonathan Young, Nate Nowel

Mechanical Engineering Design Project Class

The goal of this project was to design and assemble a remote controlled device for a competition that can maneuver through a course, collect trash units from 3D-printed trash bins, and bring them to a receptacle at the end of the course. Important factors to consider in the design involved ensuring it followed traffic laws through the course, making sure it could operate multiple times, and fit within price and space constraints. Prototypes were tested against the ability to deliver 75 percent of trash units within 5 minutes, 50 percent of trash units within 5 minutes without any traffic violations, …

Advances In Encapsulated Phase Change Materials For Integration In Thermal Management Applications, Muhammad Ghufran, David Huitink

Mechanical Engineering Faculty Publications and Presentations

Encapsulated phase change materials (ePCMs) have the potential to emerge as a key solution for efficient thermal management in various applications. This review paper explores the recent advancements in ePCMs for thermal energy storage and thermal management. We start with a basic overview of the PCMs and then performance enhancements of PCMs through the encapsulation, critical parameters for encapsulation, various encapsulation methods, and their evaluation are discussed. This review also discusses key properties and proposed figure of merit for ePCMs, impact of encapsulation on thermophysical properties, performance evaluation of ePCMs, thermal management needs, and the role of PCMs. The paper …

Dissociation Of Subjective And Objective Measures Of Trust In Vehicle Automation: A Driving Simulator Study, Samuel Petkac, Tetsuya Sato, Kun Xie, Yusuke Yamani

Psychology Faculty Publications

Trust is a crucial factor that influences human-automation interaction in surface transportation. Previous research indicates that participants tend to display higher levels of subjective trust toward lower-level automated systems compared to high-level automated systems. However, administering subjective trust measures via questionnaires can interfere with primary task performance, limiting researchers' ability to measure trust continuously in a real-world manner. In the current driving simulator study, 25 drivers using an advanced driving system (ADS) were randomly assigned to either an active (L2) or passive (L3) automated driving condition. Participants experienced eight near-miss driving scenarios with or without obstructions in a distributed driving …

Erosion Of Bermuda Grass Covered Soils, Oru-Ntui Johnwatters Nkiri

Theses and Dissertations

Earthen embankments are the most common type of embankment due to the relatively low cost, simplicity, and material availability. However, they are also the most prone to erosion related failure, typically due to overtopping and piping. Research has been conducted to identify ways to control soil erosion and protect earthen embankments with different approaches such as addition of chemicals and biopolymer to the soil, installation of protective layering (geotextiles, concrete), increased soil compaction, and use of vegetation. This thesis considers the use of Bermuda Grass to increase resistance to erosion and protect embankments from failure during overtopping. Grass coverage and …

Gut Microbiome Dynamics In Heart Failure And The Therapeutic Potential Of Nmeg-Cgrp, Kamryn Michael Gleason

Theses and Dissertations

Heart failure (HF) is increasingly recognized as a multisystem disease often linked to gut dysbiosis; however, its specific effects on gut microbial composition remain poorly understood. This study examined long-term changes in the gut microbiome in a murine HF model induced by transverse aortic constriction (TAC) and evaluated the effects of NMEG-CGRP. TAC mimics pressure overload-induced cardiac dysfunction, replicating key features of HF. CGRP, a neuropeptide with vasodilatory and cardioprotective effects, shows potential as a therapy for HF but is limited by rapid degradation. A stabilized analog, NMEG-CGRP, was used to assess its impact on cardiac and gastrointestinal health. Mice …

Performance Limiting Factors For Silicon Anodes In Lithium-Ion Batteries, Najmaddin Bashirzada

Theses and Dissertations

The rising global demand for high-performance and sustainable energy storage solutions has placed lithium-ion batteries (LIBs) at the forefront of technological progress. However, the energy density limits of traditional graphite anodes require the investigation of alternative materials. Silicon (Si), with its high theoretical capacity, is a promising anode material. Still, its practical use faces major challenges such as volumetric expansion, unstable solid electrolyte interphase (SEI) formation, and low conductivity. This thesis examines the electrochemical behavior and limitations of Si-based electrodes using coin cells and ex-situ three-electrode cells. A comparison of electrochemical testing methods – i.e., Galvanostatic Intermittent Titration Technique (GITT) …

Downwind-Upwind Flux Path Analysis Method For Model Reduction Performance Evaluations, Christian Robert Smith

Theses and Dissertations

Large, complex chemical kinetic models have long since been limited by the computational cost it takes to evaluate said model. Over time many reduction methods have been developed to combat this computational cost. However, very little has been done towards evaluating the limitations of reductions as a way of understanding the original model’s characteristics. This paper aimed to use a path flux analysis-based reduction algorithm to rapidly develop multiple reduced mechanisms for a 96 species FFCM-2 methane chemical kinetic model as well as an 858 species n-Dodecane chemical kinetic model. The goal of formulating these reduced mechanisms was to identify …

Towards Accurate First-Principles Modeling In Heterogenous Catalysis: Ethane Dehydrogenation And Hydrogenolysis Over Pt Catalysts, Mubarak Ayo Bello

Theses and Dissertations

First-principles modeling has become central to heterogeneous catalysis research, offering mechanistic insight and guiding catalyst design, yet conventional approaches often struggle to accurately describe complex catalytic systems due to methodological uncertainties, simplified assumptions, and the structural diversity of nanoparticle catalysts. This dissertation addresses these challenges using ethane dehydrogenation (EDH) and hydrogenolysis (EH) over platinum catalysts as model systems. The first study benchmarks density functional theory (DFT) functionals against the random phase approximation (RPA) for the EDH network on Pt(111), identifying cost-effective functionals and demonstrating the efficiency of BEEF-vdW ensembles for capturing functional uncertainty. The second study (addressed in prior work) …

Multiphysics Modeling, Analysis, And Design Of Ceramic Hollow Fiber Membranes For Oxygen Separation, Hamed Abdolahimansoorkhani

Theses and Dissertations

Oxygen plays a central role in numerous industrial processes. Several technologies have been reported for producing oxygen from air. Among them, oxygen transport membrane (OTM) technology—based on mixed-conducting, gas-tight ceramic membranes—has attracted significant attention due to its high oxygen selectivity, relatively low capital and operating costs, and versatility for both ex-situ and in-situ applications. Mathematical modeling of OTMs offers a powerful tool to investigate internal multi-physics transport phenomena, providing deeper insight into fundamental mechanisms while serving as a cost-effective approach for optimizing membrane stack designs.

After a comprehensive introduction, in the first part of this dissertation (chapter 2), a comprehensive …

A Building Block Approach To Certification By Analysis Applied To A Ditching Analysis, Preliminary Studies, Sean Taylor

Theses and Dissertations

Extended Twin-Engine Operations (ETOPS) certification ensures safe trans-oceanic operation of transport category aircraft. A critical aspect of ETOPS certification is compliance with ditching regulations. The importance of ditching analysis has grown significantly and come under greater scrutiny because of the ‘Miracle on the Hudson’ incident. For transport category aircraft certified under 14 CFR 25 regulations, compliance with ditching requirements, rests on two major components. First, demonstrating acceptable aircraft dynamic behavior during the ditching event and second, ensuring the airframe can withstand the loads generated because of water impact.

Historically, original equipment manufacturers (OEMs) relied on comparisons to existing aircraft with …

Implicit Neural Representation For Image Reconstruction, Canyu Zhang

Theses and Dissertations

Image reconstruction seeks to restore corrupted images and recover visual content that has been lost or degraded. Such degradation may result from low resolution, occlusion, masking, or shadow interference. This problem has become an increasingly significant research topic, as visual information plays a central role in almost every aspect of modern life. Neural network based approaches have recently emerged as highly effective solutions for this task. In particular, convolutional neural networks and transformer based architectures have demonstrated remarkable success in producing visually convincing reconstructions. However, these models remain constrained in several important ways, one of the most critical being that …

Recognizing The Unexpected: Deep Learning Across Complex Environments, Ge Song

Theses and Dissertations

Ensuring the security, trustworthiness, and operational integrity of modern autonomous and cyber-physical systems presents a critical challenge. While widely utilized in various engineering applications, such as intelligent transportation and industrial manufacturing, these systems require robust monitoring frameworks to identify unexpected anomalies in real-time, thereby maintaining operational safety and efficiency. This dissertation develops advanced deep learning methodologies for anomaly detection and health monitoring, with a particular emphasis on semisupervised reconstruction-based approaches that identify anomalies in complex environments using models trained only with normal operational patterns.

Building on this theme, the first study focuses on analyzing pedestrian behavior and detecting anomalies at …

Spectral Modeling Of Electromagnetic Radiation From Power Converters, Regan A. Varner

Theses and Dissertations

Switching power converters are increasingly utilized in contemporary electronics. They are becoming more compact and operate at higher frequencies, which contributes to radiated electromagnetic interference (EMI). This EMI is important to quantify for electromagnetic compatibility of the converters with other nearby systems. In this thesis, analytical models have been developed for both ideal and non-ideal switching waveforms, employing piecewise functions to describe time-domain waveforms, with their corresponding frequency spectra derived and compared to empirical spectra. The results demonstrate that the comparisons with measured frequency data exhibit agreement with the analytical models up to approximately 25 MHz. Additionally, our analysis indicates …

Calculating Surface Current Velocities From Video Generated From A Near Forward-Facing Camera, Colby James Weeks

Theses and Dissertations

This work presents a camera system for estimating surface currents. A combined camera and IMU system provide high resolution images and high precision orientation information, respectively. This eliminates the need for leveling and enables forward looking operation. The hardware stack includes a Lucid Vision Triton TRT162S monochrome camera, an SBG Ellipse D with dual antenna GNSS for precise pose, and an Nvidia Jetson Orin for acquisition and processing. The Ellipse D provides a hardware trigger at 10 Hz to time stamp each frame and to synchronize images with inertial measurements.

A camera calibration step estimates the intrinsic camera parameters and …

Towards Robust Bmocz Schemes For Non-Coherent Wireless Communication, Anthony Joseph Perre

Theses and Dissertations

Non-coherent communication has emerged as a promising approach to address several challenges at the physical layer. A particular scheme called binary modulation on conjugate-reciprocal zeros (BMOCZ) uses the zeros (i.e, roots) of a polynomial to convey information bits. In this thesis, we strive to improve the reliability of BMOCZ in various scenarios. In particular, we utilize machine learning (ML) methods to determine the parameters for BMOCZ and improve upon the decoding performance. Moreover, we introduce a smooshed BMOCZ variant to combat typical impairments encountered within wireless communications, including timing offsets (TOs) for noncoherent orthogonal frequency division multiplexing (OFDM). Through numerical …

Multi-Layer Decision Making For Long-Term Autonomous Mission Based On Dual Process Theory, Shruti Jadhav

Theses and Dissertations

Unmanned aerial vehicles (UAVs) are increasingly used in precision agriculture, where extended autonomous operation is required for monitoring, intervention, and field management. However, achieving long-term autonomy remains challenging due to battery constraints, environmental uncertainty, and the need to balance exploration with event-driven tasks. To address these challenges, a multi-layer decision-making framework inspired by Dual Process Theory (DPT) is developed. The framework combines reactive return-tobase strategies, exploratory navigation, and directional bias from prior missions, with a conflict-monitoring mechanism that adapts system behavior based on real-time conditions. The approach is implemented in a simulated agricultural grid environment, demonstrating improved adaptability and coverage …

Reduced Order Simulator Of A Nuclear Thermal Propulsion System, Jackson Taylor Zazzaro

Theses and Dissertations

This thesis presents the development of a reduced-order simulator for a nuclear thermal propulsion (NTP) system, designed to capture the key thermo-fluid and performance characteristics of such systems while maintaining computational efficiency. The primary objective of this work is to develop and demonstrate a modular simulation framework capable of modeling the coupled physics of an NTP reactor, nozzle, and orbital transfer system. The simulator integrates a reduced-order thermal-fluid model of the reactor, a simplified nozzle model, and an orbital transfer model, providing a comprehensive yet computationally efficient representation of the propulsion process. By employing reduced-order modeling techniques, the simulator achieves …

Rate-Dependent Interlaminar Shear Characterization In Solid-State Extruded Ultrahigh Molecular Weight Polyethylene Film Composites, Frank David Thomas Jr.

Theses and Dissertations

Ultrahigh Molecular Weight Polyethylene (UHMWPE) cross-ply [0o/90o] thin film composites are emerging as an effective material for impact applications due to their high axial strength-to-weight ratio and favorable delamination properties. Mode-II interlaminar shear (ILS) fracture-driven delamination has been shown to be a significant energy absorption mechanism. Therefore, accurately characterizing ILS behavior as a function of strain rate in these composites is essential to inform computational models. Since these composites are significantly thinner and weaker in both interlaminar shear and transverse tension than traditional carbon fiber epoxy composites, standard ILS Mode II test methods/specimens such as end-notched flexure (ENF) are expected …