Engineering Commons^™

Heat Transfer Of A 1n Thruster In A 2.5u Cubesat Module, Javier Madrid

Open Access Theses & Dissertations

With the aerospace industry expanding and moving forward with more ambitious missions, small satellites such as CubeSats have proven to be at the forefront of innovation for research satellites. This innovation have introduced complications which if gone unattended can lead to the loss of the satellite; one such complication coming in the form of propulsion heat transfer. This paper presents an investigation into the propagation of heat transfer within a 2.5 CubeSat module when a 1N thruster is fired inside it. This is done by leveraging the equation of heat transfer and comparing results to those simulated by ANSYS. Not …

Developing Executable Digital Models With Model-Based Systems Engineering – An Unmanned Aerial Vehicle Surveillance Scenario Example, Viviana Guadalupe Lopez

Theses and Dissertations

There is an increase in complexity in modern systems that causes inconsistencies in the iterative exchange loops of the system design process and in turn, demands greater quality of system organization and optimization techniques. A recent transition from document-centric systems engineering to Model-Based Systems Engineering (MBSE) is being documented in literature from various industries to address these issues. This study aims to investigate how MBSE can be used as a starting point in developing digital twins (DT). Specifically, the adoption of MBSE for realizing DT has been investigated, resulting in various literature reviews that indicate the most prevalent methodologies and …

Wave Excited Mass-Spring-Damper System For A Self-Recharging Autonomous Underwater Vehicle, Mahmodul Hasan Maheen

Theses and Dissertations

Autonomous underwater vehicles' (AUVs) endurance is constrained by the lifetime of their batteries and the distance that tether wires can traverse. Solving the endurance problem of AUV using the enormous potential of ocean wave energy is the motivation behind this thesis. The objective of this research is to model a mass-spring-damper system to emulate the permanent magnet linear generator (PMLG) of a self-recharging AUV and identify its energy absorption capability through numerical simulation and experimental testing. The research activities started with modeling and fabricating a 1:5 scale model. The scaling was done by comparing the most common AUV size of …

The Effects Of Carbon Coating On The Electrochemical Performance Of Metal-Oxide Short Fiber Anodes For Lithium-Ion Batteries, David A. Sanchez

Theses and Dissertations

This thesis focuses on the process of oxidizing centrifugally spun precursor fibers and the subsequent process of carbon coating via chemical vapor deposition (CVD) for use as anode material in lithium-ion batteries (LIBs). Metal oxides have been studied as a potential replacement for graphite as they have been shown to have high theoretical capacities, good electronic conductivity, and can be synthesized using low-cost, scalable methods. However, metal oxides with high theoretical capacities also have low cycle life. To avoid this, metal oxides have been integrated with carbon to expand their life cycle. The work in this thesis shows the synthesis …

2023 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2023.

Drop Impact On Dry And Liquid Infused Substrates With Micro-Wells., Ahmed Nazrul Islam

Electronic Theses and Dissertations

Drop impact on different types of surfaces are important physical concepts that are routinely found in day-to-day life and such studies have immense application for various types of industries. One such important application of drop dynamics is in the field of aviation science which is concerned of very large freezing drizzle drops impacting on airplane wings. Such drops are known as supercooled large droplets (SLD), and they pose a great risk and have been long known to have caused notable accidents in the past. SLDs are liquid drops that can remain in the state of liquid phase and grow into …

A Predictive Analysis Of The Influence Of Thickness And Length On The Curvature Of Square Bistable Carbon Fiber Reinforced Composite Laminates, Stephan Terry

All Theses

This thesis presents a predictive analysis of the stability of square bistable carbon fiber reinforced composite laminates under various loading conditions. The stability of these laminates is essential to their performance and longevity and is influenced by factors such as thickness and length. Analytical and numerical techniques are used to model the behavior of these laminates, and experimental tests are conducted to validate the models. The findings of this research have implications for the design and optimization of square bistable carbon fiber reinforced composites.

The study investigates the relationships between the side length and thickness of square laminates for bistability. …

Multifunctional Additive Manufacturing And Multiphysics Numerical Investigations Of Carbon Fiber Structural Battery Composite Using A Drop-On-Demand Method With In-Situ Consolidation, Xiangyang Dong, Yuekun Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lightweight Carbon Fiber Structural Battery Composite Has Great Potential in Increasing Structural Energy Storage Efficiency for Multifunctional Applications. However, It is Still Challenging to Design Carbon Fiber Multifunctional Composite Due to Lack of Proper Manufacturing Methods. in This Study, an Integrated Multifunctional Design and Fabrication Approach is Developed by Combining a Drop-On-Demand Additive Manufacturing Method with a Multiphysics Numerical Model to Guide the Development of the New Multifunctional Composite. through Deposition with In-Situ Consolidation, the Function and Thickness of Each Carbon Fiber Layer as Well as its Fiber Volume Fraction Are Accurately Controlled. Decreasing Layer Thickness Improves Flexural Properties. the …

Metastability And Degradation In Cu(In,Ga)Se2 Thin-Film Solar Cells, Mohsen Jahandardoost

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cu(In,Ga)(S,Se)2 or CIGS is a thin-film semiconductor that has shown a device efficiency of 23.35% and 24.2% for single-junction and perovskite/CIGS tandem solar cells, respectively. CIGS offers promising properties such as tunable bandgap and ease of processing making them great candidates for thin-film tandem devices. However, knowledge of the effect of material defects, buffer materials, and post-deposition treatment (PDT) on degradation and metastability behavior in these devices is not well understood.In this dissertation, metastability and long-term degradation of CIGS thin-film solar cells have been investigated under combinatorial stress factors of heat, light, and voltage bias to systematically understand the effect …

Improving The Learning Efficiency Of Adaptive Optimal Control In Information-Limited Environments, Omar Ghassan Qasem

Theses and Dissertations

This work investigates the adaptive optimal control problems for continuous-time linear and nonlinear systems. A novel adaptive dynamic programming method, namely hybrid iteration (HI) is presented. Different from the existing adaptive dynamic programming methods, i.e., policy iteration (PI) and value iteration (VI), the HI does not require an initial admissible control policy compared to the PI. On the other hand, the HI converges to the optimal control policy in much less learning iterations and CPU time compared to the VI due to the ensured quadratic rate of convergence of the HI method, which is much faster than the sub-linear convergence …

Biomimicry Of Natural Reef Hydrodynamics In An Artificial Spur And Groove Reef Formation, Emilee Alaine Wissmach

Theses and Dissertations

Coral reef populations have rapidly been declining in coastal waters worldwide. Losing these ecosystems results not only in a loss of habitat and biodiversity, but also a loss of wave attenuation and subsequent coastal protection. Ongoing projects seek to rehabilitate and/or replace destroyed reefs with artificial structures like reef balls and rip-rap, but none perform as well as a healthy, natural reef. This project created scale modules mimicking the reef-crest and spur-and-groove (SAG) zones commonly found in natural reefs and used these models to support new efforts in artificial reef design. The modular structure consists of three different components including: …

Heat Transfer In Microchannel Compact Heat Exchanger, Mohammed Al-Khateri

Theses

This study aims to investigate heat transfer in a miniaturized channel heat exchanger and effectiveness for given real-life design. The main objective of the study is to develop and build a high-performance heat exchanger for thermal management in automotive application using typical radiator manufacturing techniques. This research uses experimental and model-based investigation. It conceptualizes the Miniaturized Channel Heat Exchangers (MCHX) model-based study for demonstrating the design of miniaturized channel heat exchangers, manufacture, and study the heat exchanger effectiveness by validating the developed mathematical model experimentally. The proposed design of the MCHX is to use extruded tubes containing miniaturized channels as …

Electrochemical Investigation Of Copperzirconium Based Metallic Glass Cu₅₁Zr₃₀Hf₁₄Ag₅, Tamim Mohammad Ahmad

Theses

This thesis is concerned with the electrochemical investigation of the copper-zirconium

based metallic glass Cu₅₁Zr₃₀Hf₁₄Ag₅. Studying the corrosion behavior of the novel melt-spun metallic glass ribbons contributes to further research on the possibility of building future bio-implants. The objectives of this thesis are to synthesize the metallic glass ribbons which are free from cytotoxic elements using melt spinning technique, verify their amorphous nature using X-ray diffraction method, study the corrosion behavior using Potentiodynamic polarization and Electrochemical Impedance Spectroscopy in different acidic, neutral and basic solutions, and finally examine the surface morphology of …

An Exploration Of The Application Of Desalination In Disaster Relief, Emma Sager

Senior Honors Theses

This paper aims to explore the application of small-scale desalination systems to provide clean water in the wake of marine natural disasters. A lack of clean water is a devastating impact of many natural disasters. Desalination technologies, both thermal and membrane, show potential for being scaled down and self-powered by renewable energy. Desalination can transform ocean water and contaminated drinking water with a high salt content into drinkable, usable water. While these techniques are not perfected, and the solution to a need for clean water is multifaceted, desalination shows potential. Through further research and ever-advancing technology, small-scale desalination could develop …

Rattus Norvegicus As A Biological Detector Of Clandestine Remains And The Use Of Ultrasonic Vocalizations As A Locating Mechanism, Gabrielle M. Johnston

Master's Theses

In investigations, locating missing persons and clandestine remains are imperative. One way that first responder and police agencies can search for the remains is by using cadaver dogs as biological detectors. Cadaver dogs are typically used due to their olfactory sensitivity and ability to detect low concentrations of volatile organic compounds produced by biological remains. Cadaver dogs are typically chosen for their stamina, agility, and olfactory sensitivity. However, what is not taken into account often is the size of the animal and the expense of maintaining and training the animal. Cadaver dogs are typically large breeds that cannot fit in …

Self-Powered Triboelectric Mems Accelerometer, Mohammad Alzgool, Yu Tian, Benyamin Davaji, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

A self-powered triboelectric accelerometer miniaturized to the micro-scale is presented. This micro triboelectric accelerometer (MTEA) was fabricated using CMOS-compatible processes. The design followed the triboelectric nanogenerators made in meso-scale and operates in the contact-separation mode. The scaled-down, multilayer design enabled fabrication using microelectromechanical systems (MEMS) technology. The MTEA was made using an aluminum and polyimide triboelectric pair that generated charges on the contact. A square movable plate that is 2 mm x 2 mm was fabricated with 1 μm thickness. Then, the fabricated MTEA was excited by a mini-shaker at known frequencies (0.1–7 kHz) and accelerations (1–10 g), and the …

The Characterization Of Atmospheric Turbulence And Its Effect On Laser Beam Propagation, Michael Cox

All Theses

Having a controlled environment to measure atmospheric turbulence is essential to understanding its effects on different laser beam characteristics. The Clemson Variable Turbulence Generator (VTG) has the capability to propagate a laser beam up to 100 m and be able to dial many turbulence settings up to a heat flux of 357 W/m². A high-speed camera, power detector, and high-resolution temperature probes characterize the VTG with theoretical turbulence spectrums. The exponent associated with the Rayleigh-Bénard (RB) temperature structure constant equation is studied. Two different laser beam profiles are used throughout this work: Gaussian and Asymmetric Perfect Vortex (APV). …

Me-Em Enewsbrief, March 2023, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

The Synthesis And Characterization Of Metal Oxide Nanomaterial-Based Composites And Their Use As Antibacterial Agents, Jo A. Sanchez

Theses and Dissertations

The work presented in this thesis discusses the antibacterial properties of various metal oxides and metal oxide/polymer composite fibers. Polyvinylpyrrolidone (PVP) fibers embedded with Zinc Oxide nanoparticles (ZnO NPs) were prepared by centrifugal spinning from PVP aqueous solutions) and ZnO NPs. The ZnO NPs were synthesized and coated with different surfactants, cetyltrimethylammonium bromide (CTAB) and hexadecyltrimethylammonium bromide (HTAB). The effect of surfactant coating on the antibacterial activity of ZnO NPs and PVP/ZnO nanocomposite fibers against escherichia coli (e. coli) and bacillus megaterium (b. megaterium) bacteria was systematically investigated. The results showed that coating the ZnO NPs …

Self-Assembly Of Exfoliated Graphene Flakes As Anticorrosive Coatings For Additive Manufactured Steels, Kaleb Hood, Wen Qian, Savannah Krupa, Annie Dao, Sarah Ahmed, Samuel Olson, Jun Jiao, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

This study demonstrates the feasibility of using liquid exfoliation of expandable graphite into multilayer exfoliated graphene flakes (EGFs) to form a self-assembled thin film on an air–water interface. The film can coat the surface of additive manufactured (AM) steel substrates to enhance surface properties, specifically AM 316 stainless-steel (AM316), AM 8620 steel (AM8620), and samples of the same alloys made by conventional manufacturing (CM) processes. Liquid exfoliation offers a high yield route for an EGF coating that can cover up to 95% of the sample surface with a single application. The thin, flexible EGFs can coat a rough AM metal …

Direct Spectroscopic Observation Of Cross-Plane Heat Transfer In A Two-Dimensional Van Der Waals Heterostructure, Du Chen, Matthieu Fortin-Deschênes, Yuchen Lou, Huiju Lee, Kenji Watanabe, Takaaki Taniguchi, Fengnian Xia, Peijun Guo, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

Two-dimensional (2D) transition metal chalcogenides (TMDs) have drawn significant attention in recent years due to their extraordinary optical and electronic properties. As heat transfer plays an important role in device performance, various methods such as optothermal Raman spectroscopy and time-domain thermoreflectance have been developed to measure the thermal conductivity and interfacial thermal conductance in 2D van der Waals (vdW) heterostructures. Here, we employ the vibrational-pump-visible-probe (VPVP) spectroscopy to directly visualize the heat transfer process in a heterostructure of multilayer h-BN and monolayer WS2. Following an impulsive vibrational excitation of h-BN in the mid-infrared, we probe the heat transfer …

Flow Development And Entrainment In Turbulent Particle-Laden Jets, Laura K. Shannon, Bianca Viggiano, Raúl Bayoán Cal, L. G. Mastin, Alexa R. Van Eaton, Stephen Solovitz

Mechanical and Materials Engineering Faculty Publications and Presentations

Explosive eruptions expel volcanic gases and particles at high pressures and velocities. Within this multiphase fluid, small ash particles affect the flow dynamics, impacting mixing, entrainment, turbulence, and aggregation. To examine the role of turbulent particle behavior, we conducted an analogue experiment using a particle-laden jet. We used compressed air as the carrier fluid, considering turbulent conditions at Reynolds numbers from approximately 5,000 to 20,000. Two different particles were examined: 14-μm diameter solid nickel spheres and 13-μm diameter hollow glass spheres. These resulted in Stokes numbers between 1 and 35 based on the convective scale. The particle mass percentage in …

Deep Reinforcement Learning And Game Theoretic Monte Carlo Decision Process For Safe And Efficient Lane Change Maneuver And Speed Management, Shahab Karimi

All Dissertations

Predicting the states of the surrounding traffic is one of the major problems in automated driving. Maneuvers such as lane change, merge, and exit management could pose challenges in the absence of intervehicular communication and can benefit from driver behavior prediction. Predicting the motion of surrounding vehicles and trajectory planning need to be computationally efficient for real-time implementation. This dissertation presents a decision process model for real-time automated lane change and speed management in highway and urban traffic. In lane change and merge maneuvers, it is important to know how neighboring vehicles will act in the imminent future. Human driver …

Molecular Dynamics Simulation On Molybdenum Disulfide: Thermal-Mechanical Properties And Phase Transitions Under External Loading, Mahabubur Rahman

All Dissertations

Due to their remarkable properties, transition metal dichalcogenides (TMDs) have received much scientific interest throughout the past decade. Two layers of chalcogen atoms (S, Se, Te) sandwich a layer of transition metal atoms (Mo, W, Ta) to form the three-atom thick unit cell in TMDs. The interaction between TMD "single layers" is mediated by neighboring chalcogen planes and bonded by Van der Waals forces. Due to this weak out-of-plane interaction, bulk samples can be thinned down to a single layer by exfoliation. Among the TMDs, Molybdenum Disulfide (MoS₂) shows promise in the field of electronics, optics, and sensing …

Near-Optimal Control Of A Quadcopter Using Reinforcement Learning, Alberto Velazquez-Estrada

Theses and Dissertations

This paper presents a novel control method for quadcopters that achieves near-optimal tracking control for input-affine nonlinear quadcopter dynamics. The method uses a reinforcement learning algorithm called Single Network Adaptive Critics (SNAC), which approximates a solution to the discrete-time Hamilton-Jacobi-Bellman (DT-HJB) equation using a single neural network trained offline. The control method involves two SNAC controllers, with the outer loop controlling the linear position and velocities (position control) and the inner loop controlling the angular position and velocities (attitude control). The resulting quadcopter controller provides optimal feedback control and tracks a trajectory for an infinite-horizon, and it is compared with …

Design Of A Miniature Robotic Surgery Technology Demonstration Payload For Orbital Spaceflight, Rachael A. Wagner

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis describes the design of a technology demonstration payload that will test robotic surgery while aboard a 2024 expedition of the International Space Station (ISS). The payload utilizes a new miniature surgical robot to complete simulated surgical tasks on orbit, both autonomously and while remotely controlled by an Earth-based user. The experiment investigates the effects of microgravity and latency on robotic surgery, with the following goals:

1. Demonstrate the use of a miniature robotic surgical system in microgravity through performing simulated surgical tasks.

2. Quantify the effects of microgravity on robotic surgical techniques including forces, torques, and kinematic accuracy. …

Blood Flow Regulates Atherosclerosis Progression And Regression, Morgan A. Schake

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Atherosclerosis is the most prevalent pathology of cardiovascular disease with no known cure. Despite the many systemic risk factors for atherosclerosis, plaques do not form randomly in the vasculature. Instead, they form around bifurcations and the inner curvature of highly curving arterial segments that contain so-called disturbed blood flow that is low in magnitude and multidirectional over the cardiac cycle. Conversely, straight, non-bifurcated arterial segments that contain moderate-to-high and unidirectional (i.e., normal) blood flow are protected from plaque development. Thus, blood flow is a key regulator of atherosclerosis that may be able to be leveraged to develop new therapeutics. Towards …

Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm

All Dissertations

Electrically assisted manufacturing (EAM) is the direct application of an electric current to a workpiece during manufacturing. This advanced manufacturing process has been shown to produce anomalous effects which extend beyond the current state of modeling of thermal influences. These purported non-thermal effects have collectively been termed electroplastic effects (EPEs).

While there is a distinct difference in results between steady-state (ideal DC) testing and pulsed current testing, the very definition of these two EAM methods has not been well established. A "long" pulse may be considered DC current; a "short" pulse may produce electroplastic effects; and even "steady-state" current shapes …

Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin

All Dissertations

Inverse problems involve extracting the internal structure of a physical system from noisy measurement data. In many fields, the Bayesian inference is used to address the ill-conditioned nature of the inverse problem by incorporating prior information through an initial distribution. In the nonparametric Bayesian framework, surrogate models such as Gaussian Processes or Deep Neural Networks are used as flexible and effective probabilistic modeling tools to overcome the high-dimensional curse and reduce computational costs. In practical systems and computer models, uncertainties can be addressed through parameter calibration, sensitivity analysis, and uncertainty quantification, leading to improved reliability and robustness of decision and …

A Value-Based Sequential Optimization Framework For Efficient Materials Design Considering Uncertainty And Variability, Maher Alghalayini

All Dissertations

Many problems in engineering and science can be framed as decision problems in which we choose values for decision variables that lead to desired outcomes. Notable examples include maximizing lift in airplane wing design, improving the efficiency of a power plant, or identifying processing protocols resulting in structural materials with desired mechanical properties. These problems typically involve a significant degree of uncertainty about the often-complex underlying relationships between the decision variables and the outcomes. Solving such decision problems involves the use of computational models or physical experimentation to generate data to make predictions and test hypotheses. As a result, both …