Mechanical Engineering Commons^™

Mathematical Modeling Of Heat And Mass Transfer In Multilayer Systems, Girish Krishnan

Mechanical and Aerospace Engineering Dissertations - Archive

Multilayer systems are commonly found in a number of engineering devices like Li-ion cells and vertically integrated semiconductor devices. Li-ion cells are widely used for various engineering applications, but they come with a drawback in the form of thermal runaway, and thermal abuse is one of the scenarios that leads to thermal runaway. On the other hand, heterogenous integration in chip and package level architectures is being implemented to keep up with Moore’s law. Modeling of heat and mass transfer in these systems is a topic of interest to improve performance and reliability.

The first segment of this dissertation will …

Development Of A 3d Printed Optimization-Driven Aeroelastically Scaled Wind Tunnel Model For High Aspect Ratio Flying Wings, Mikaela K. Leevy

Mechanical and Aerospace Engineering Theses - Archive

Design optimization coupled with 3D printing and parametric CAD offers a unique approach to investigating flutter phenomena by creating low-cost iterative aeroelastic wind tunnel models. Recently, there is an interest in studying flutter phenomena at low air speeds in flying wing configurations. The X-56 experimental flying wing was designed to investigate flutter phenomena and flutter suppression, which makes the X-56 a logical choice for the full-scale model. The goal of this work is to optimize, physically print, and geometrically characterize a scaled aeroelastic wind tunnel model. The 18% reduced scale X-56 model was optimized by matching the mode shapes to …

Nonlinear Guidance And Control Of Unmanned Aerial Manipulators For Delivering A Payload On A Moving Platform, Ravi Gyawali

Mechanical and Aerospace Engineering Theses - Archive

Unmanned Aerial manipulators (UAMs) are a class of Unmanned Aerial Vehicles (UAVs) equipped with a manipulator. By combining the aerial mobility of a UAV with a manipulator's dexterity, these hybrid systems can perform a wide range of complex tasks while reducing risks and costs. As a result, they are increasingly being utilized for military, industrial, and agricultural applications.

The thesis presents a novel approach for a multi-UAM system to collaboratively deliver a payload on a stationary or maneuvering platform. A sliding-mode-based guidance law, sourced from existing literature, is integrated with a combined control technique for the UAVs and their respective …

Electophorectic Deposition For Novel Nanodecorated Electrodes Towards Thermally Charging Supercapacitor (Tcsc), Ashish Thakur

Mechanical and Aerospace Engineering Theses - Archive

Thermally Self-Charging Supercapacitors (TSCS) are a promising new technology that can harvest waste heat to produce electrical energy. The Soret effect is exploited wherein ion separation due a temperature gradient leads to a potential difference. Here, we use electrophoretic deposition (EPD), a room-temperature, scalable, universal technique, to obtain CNT decorated electrodes for fabrication of such TSCS devices with ionic liquid electrolyte. We further show that precise control over deposition parameters can be used for optimization of TSCS performance metrics. TSCS devices were tested by several characterization standards, indicating the superior performance of nanodecorated electrodes obtained by EPD.

Dynamics Of Separated Flows In Diffusers With Vortex Generators, Sandeep Eldho James

Mechanical and Aerospace Engineering Dissertations - Archive

Flow through curved diffusers is complicated due to the possibility of flow separation and secondary flows. Vortex generators (VGs) are a class of passive flow separation control devices used to improve the flow quality in curved diffusers by suppressing flow separation. However, the literature review demands an in-depth investigation on the physical mechanisms related to flow separation control. Thus, this study aims to improve the understanding of the underlying flow physics associated with VG-induced flow separation control in confined flows. The chosen geometry for this study is a well-documented asymmetric diffuser which exhibits a mild flow separation.

The theoretical formulation …

Generalizable Fugitive Carrier Method For 3d Printing Of Hydrogels, Hakan Arslan

Mechanical and Aerospace Engineering Dissertations - Archive

Hydrogels, with physical characteristics resembling biological soft tissues, hold great potential for bioinspired and biomedical applications. However, using them in additive manufacturing systems has challenges because of their poor mechanical and rheological properties. In response to these challenges, we introduce a fugitive carrier method, a novel and generalizable approach for materials incompatible with pneumatic-based extrusion three-dimensional (3D) printers. Our developed fugitive carrier method allows the 3D printing of a broad spectrum of hydrogel precursors with low viscosity while retaining their inherent properties. This technique has been successfully demonstrated by creating biomimetic structures with anisotropic and programmable systems utilizing temperature-sensitive hydrogel …

Machine Learning-Based Methodology For Multi-Objective And Multi-Design Variable Optimization Of Finned Heat Sinks And Evaluation Of Electrochemical Additive Manufactured Heat Sink Designs For Single-Phase Immersion Cooling, Joseph F. Herring Ii

Mechanical and Aerospace Engineering Dissertations - Archive

Traditional air-cooling along with corresponding heat sinks are beginning to reach performance limits, requiring lower air-supply temperatures and higher air-supply flowrates, in order to meet the rising thermal management requirements of high power-density electronics. A switch from air-cooling to single-phase immersion cooling provides significant thermal performance improvement and reliability benefits. When hardware which is designed for air cooling is implemented within a single-phase immersion cooling regime, optimization of the heat sinks provides additional thermal performance improvements. This work investigates performance of a machine learning (ML) approach to building a predictive model of the multi objective and multi-design variable optimization of …

Design And Analysis Of Electrochemical Additive Manufacturing Based Cold Plates And Heat Sinks For Enhanced Electronics Cooling And Temperature-Dependent Density Characterization Of Phase Change Materials, Jacob Lamotte-Dawaghreh

Mechanical and Aerospace Engineering Dissertations - Archive

The body of work that comprises this dissertation is divided into two main sections. The first section is regarding novel heat sink and cold plate designs that leverage a metal additive manufacturing process called electrochemical additive manufacturing (ECAM) to drive increased thermal performance. The continuous advancements in electronics computational capabilities have resulted in ever-increasing thermal loads at the component and data center server level. These strides within the field are soon to be compounded by the rise of artificial intelligence and machine learning technologies. Traditionally, high performance electronics components have been able to be cooled by forced-air cooling; however, the …

Graphene Reinforced Polymer Composite For Small-Scale Vertical Axis Wind Turbine Rotors, Kunal A. Bachim

Mechanical and Aerospace Engineering Theses - Archive

Polymers have evolved as an indispensable asset in various sectors ranging from packaging and construction to energy and aerospace. However, the accumulation of polymer waste poses a necessity to shift toward sustainable waste management processes. Mechanical recycling is a primary method in establishing a circular economy approach for polymers. However, a fundamental challenge arises in this process: a decrease in the mechanical performance of the recycled product compared to that of its pristine counterpart.

This project addresses the challenge of enhancing the recyclability of polyethylene terephthalate (PET) from discarded polymer material by incorporating graphene nanoparticles into the polymer matrix during …

Development And Application Of Guided Mode Resonance Biosensor Platforms For Highly Sensitive And Real-Time Cell Killing Assays, Seyedmohsen Vaziri

Electrical Engineering Dissertations - Archive

In this work, we developed and investigated the cancer cell killing efficacy of different instances using real-time high-sensitivity measurements facilitated by Guided-Mode Resonance (GMR) sensors. The GMR biosensor technology detects shifts in the spectral peak caused by changes in the refractive index of the surrounding medium, offering a label-free method for monitoring cellular events.

A549 cell line wild type and HER2 knockout (lung cancer cells) were exposed to different concentrations of Triton X-100 and ADC (Herceptin with αHFc-CL-DMDM). The GMR-based cell killing assay demonstrated exceptional sensitivity and specificity, with shifts in wavelength exhibiting a robust correlation with cell viability and …

Analytical And Simulation Modelling Of The Thermal Runaway Phenomenon In Mosfet Semiconductors, Arun Narasimhan

Mechanical and Aerospace Engineering Theses - Archive

MOSFETS (Metal Oxide Semiconductor Field Effect Transistors) are a popular type of active current carrying device. The need for higher performance and faster switching times has led to designs which use low gate source voltage where heat conduction is dominated by charge carriers. The concentration of charge carriers increases with an increase in temperature, causing more current to flow as the temperature increases. As a result, the device draws more current as temperature increases, causing further temperature rise. As the device temperature increased, it would draw more current and cause further temperature rise. This is a positive feedback loop which …

Numerical Simulation And Optimization Of Fin Configurations For Enhanced Heat Sink Performance In Aluminum And Copper Materials, Rimpy Singh

Mechanical and Aerospace Engineering Theses - Archive

The constant evolution of data centers and high-power electronic systems has raised critical challenges in heat dissipation and thermal management. Single-phase immersion cooling, where electronic components are submerged in a thermally conductive but non-electrically conductive liquid (dielectric liquid), offers improved heat dissipation capabilities and emerges as a promising alternative to traditional air-cooling methods, which often fail to meet the thermal demands of densely packed, high-power systems. This study investigates and compares the thermal performance of aluminum and copper heat sinks with fin thicknesses of 0.33 mm and 0.54 mm, respectively, using finite element analysis based on computational fluid dynamics (CFD) …

Advanced Thermal Management Solutions For High-Powered Chips: A Comprehensive Study On Immersion Cooling And Electrochemical Additive Manufacturing-Based Cold Plates, Gautam Gupta

Mechanical and Aerospace Engineering Dissertations - Archive

This dissertation investigates advanced thermal management strategies for high-performance computing systems to address the escalating thermal challenges posed by increasing power densities and computational demands. Chapter 1 evaluates the efficacy of forced convection Single-Phase Immersion Cooling (SPIC) with a dielectric fluid (EC-110) compared to traditional air cooling for a 776 W server. Computational Fluid Dynamics (CFD) simulations demonstrate significant reductions in chip junction temperatures, maximum Dual In-line Memory Module (DIMM) temperatures, and server pressure drop with immersion cooling, highlighting its superior heat dissipation capabilities.

Chapter 2 delves into the comparative analysis of forced and natural convection Single-Phase Immersion Cooling techniques. …

Reliability Assessment Of 2.5d Heterogenous Integrated Circuits, Cu-Cu Hybrid Bonded Interconnects & Thermo-Mechanical Assessment Of Substrates In Two-Phase Immersion Cooling, Akshay Boovanahally Lakshminarayana

Mechanical and Aerospace Engineering Dissertations - Archive

Moore’s law has predicted the growth of semiconductor industry for the last 50 years by providing a template for silicon scaling and homogenous system on chip integration of multiple circuits. Lately, this trend has been declining due to the increased power density and functionality and increasing chip size to accommodate this. Moving forward, heterogeneous integration of chiplets will improve the silicon yield by integrating multiple multi-functional chiplets that are of smaller area onto an interposer or a substrate in 2.5D, 3D or 3.5 D architectures. In this study, computational analysis is done on the impact of design parameters and material …

Towards The Development Of A Unified Synthesis System Framework: Advancement Of Avds Towards A Generic, Multi-Disciplinary, And Multi-Fidelity Aerospace Vehicle Design Environment, Ian Wesley Maynard

Mechanical and Aerospace Engineering Dissertations - Archive

At the start of any design program for the development of a novel aerospace vehicle, there can be millions of design, mission, and technology trades to be explored. Design software is needed that can modularly adapt itself such that it can be generically applied to a wide variety of aerospace applications. It needs to be automated such that it can ‘stitch’ together and generate synthesis codes using a wide variety of disciplinary methods including geometry, aerodynamics, propulsion, trajectory, weights, stability and control, cost, etc. It should also be able to modularly switch the multi-disciplinary synthesis execution process in the synthesis …

Design And Demonstration Of An Inertial-Stabilized Single-Axis Headlamp For Mobile Systems, Thomas Avery Allsup

Mechanical and Aerospace Engineering Dissertations - Archive

The introduction of adaptive headlamps has added left and right movement of the headlamps to enhance the vision of the driver during a turn at night. Adaptive headlamps also allow up and down motion of headlamps in either two discrete positions with low and high beams based on vehicle speed and oncoming traffic lights or using the vehicle suspension measurement to adjust headlamp beam angles in any angle between low and high. Using the vehicle suspension ignores the roadway influence on where the headlamps should be positioned to illuminate the roadway for the driver. This dissertation develops governing equations and …

On The Development Of A Sensing System Methodology To Evaluate The Viscoelastic Properties Of Soft Tissues As A Means Of Disease Prognosis, Shashank S. Kumat

Mechanical and Aerospace Engineering Dissertations - Archive

Identification of tissue viscoelastic properties could provide valuable information for assessing its healthiness or disease state. Current technologies present challenges to access and perform localized tissue assessment in confined spaces in the human body through contact indentation/palpation. As such, there is a need for a diagnostic system capable of measuring tissue relaxation response at the local site by accessing the tissue through a natural orifice. This dissertation presents a strain gauge-based uniaxial micro-force sensor, part of the aforementioned system, capable of measuring tissue response data in confined human space environments. A sensing system design methodology is developed and presented. The …

Optimizing Energy Efficiency And Performance In High-Performance Computing Through Advanced Direct-To-Chip Liquid Cooling And Labview-Based Monitoring And Analysis, Chandraprakash Ashok Hinge

Mechanical and Aerospace Engineering Dissertations - Archive

This research endeavors to significantly enhance energy efficiency and performance in the realm of high-performance computing (HPC). This goal is pursued through a synergistic approach that leverages advanced direct-to-chip liquid cooling systems and integrates LabVIEW for real-time monitoring and analysis within data centers. The primary aims of this study are manifold. First, it seeks to evaluate the effectiveness of different single-phase liquid coolants when employed in direct-to-chip cold plate cooling for HPC systems. Additionally, the research focuses on characterizing row manifolds, crucial elements in the design of efficient data centers. The study also endeavors to devise a strategic control mechanism …

Multiple Dipole Source Position And Orientation Estimation Using Non-Invasive Eeg-Like Signals, Saina Namazifard

Mechanical and Aerospace Engineering Dissertations - Archive

The human brain comprises of neurons that connect with each other via electrical signals. One can record and measure these activities using an electroencephalogram (EEG). An essential use of the EEG is in locating the generating source of these signals, usually approximated by dipoles. This is important because, in some particular circumstances, neurons may not function optimally and could make the equivalent dipole generate abnormal signals. This could be a result of seizures or other brain disorders. In order to isolate such disorders, the challenge is to find a non-invasive way to locate the anomalous source. This research aims to …

Thermo-Mechanical Analysis Of Heterogenous Integrated Packages And Immersion Cooling Of Data Center Servers, Krishna Bhavana Sivaraju

Mechanical and Aerospace Engineering Dissertations - Archive

III-V materials such as Gallium Arsenide (GaAs) and Indium Phosphide (InP) are used as substrates for opto-electronic devices like vertical cavity surface emitting lasers (VCSEL), edge emitting lasers and light emitting diodes. System in Package integration of the III-V materials to silicon requires a reliable bonding technique. Though there are several bonding techniques like direct wafer bonding like hetero-epitaxially grown islands on a silicon wafer bonding enable the bonding, flip-chip bonding is used in this study owing to its superior electrical connectivity, mechanical reliability, heat conduction capability and ease of fabrication due to self-alignment. Finite element models of four different …

Analysis Of A Nanoparticle’S Dynamics In An Optical Tweezer, Vatsal Asitkumar Joshi

Mechanical and Aerospace Engineering Dissertations - Archive

This work presents a simulation and experimental analysis of a nanoparticle's motion in an optical tweezer. Specifically, different simulation and analysis techniques are developed to investigate a suspected regime change in the dynamics of the micro/nano particles from overdamped to underdamped motion as the particle size reduces to submicron scale. Moreover, the simulation techniques developed here provide accurate prediction of the particle dynamics along with low computation time. Finally, the experimental setup developed here provides new experimental data that help answer the question of the regime change with increased certainty. Micro- and nano- scale systems, such as an optical tweezer, …

High Magnification Surface Topography Based Digital Image Correlation (Dic) For Identifying Damage Accumulation And Crack Growth In Polycrystalline Nickel, Arash Valiollahi

Mechanical and Aerospace Engineering Dissertations - Archive

Damage index parameters that have been formulated to identify damage localization in plastically deformed materials typically require all six stress or strain components. Recently, simulations through Crystal Plasticity Finite Element Method (CPFEM) have been widely used to extract damage initiation parameters. However, these models are rarely verified due to the challenges in measuring the out-of-plane deformation/strain experimentally. A damage index combining the effective plastic strain and surface roughness change is investigated for identifying damage accumulation sites and predicting crack propagation path in polycrystalline pure Nickel. A novel Digital Image Correlation (DIC) technique is developed to measure both in-plane and out-of-plane …

Investigation Of Thermal Performance Enhancement And Thermo-Mechanical Assessment Of Ite Using Single-Phase Immersion Cooling Technology, Pratik Bansode

Mechanical and Aerospace Engineering Dissertations - Archive

The use of air-cooling as a thermal management technique in data centers has consistently maintained its importance, however its efficacy is limited to CPUs with lower power requirements. The expenses and energy use related to the air circulation process for high-power density racks are deemed excessively costly. The limits of air cooling have aroused concerns owing to its low specific heat capacity and poor thermal conductivity, which result in reduced effectiveness. Consequently, a substantial discourse has emerged about alternate and effective cooling methods that provide supplementary advantages, such as the recuperation of waste heat. In light of the limitations associated …

Optimal Aggressive Constrained Trajectory Synthesis And Control For Multi-Copters, Tsung-Liang Liu

Mechanical and Aerospace Engineering Dissertations - Archive

Multi-copters have become increasingly popular in recent years due to their availability, mobility, agility, and flexibility. They serve as excellent platforms for control experiments and various applications. Their characteristics also make them an attractive choice for high-speed aerial navigation in complex environments. Numerous studies have been conducted on aggressive trajectory generation and maneuver tracking. However, the level of aggressiveness achievable depends on the optimality of the trajectory plan and the dynamic capabilities of the vehicle. It would be valuable if one can generate a trajectory that fully utilizes the dynamic capabilities of the multi-copter while accommodating specific maneuvers at predetermined …

Analyzing The Thermomechanical Performance Of Tg400g Material Substrate Core Under Immersion Cooling, Venkateswar Vishnu Tirupati Venkatachal

Mechanical and Aerospace Engineering Theses - Archive

The relentless surge in demand for seamless information exchange through consumer electronics, driven by the indispensable role of the Internet, has given rise to an unprecedented need for data centres. Yet, the energy consumption of conventional data centres, where a significant one-third of energy usage is attributed solely to cooling, has triggered an urgent quest for energy-efficient solutions. Immersion cooling technology appears as a promising contender due to its exceptional prowess in managing thermal energy. However, its potential impact on the reliability of IT equipment needs a more profound exploration before widespread adoption can be realized. This study embarks on …

Design And Implementation Of A Behavioral Sequence Framework For Human-Robot Interaction Utilizing Brain-Computer Interface And Haptic Feedback, Sudip Hazra, Shane Whitaker, Panos S. Shiakolas

Mechanical and Aerospace Student Research - Archive

In assistive robotics, research in Brain Computer Interface aims to understand human intent to enhance Human- Robot Interaction and augment human performance. In this research, a framework to enable a person with an upper limb disability to use an assistive system towards maintaining self-reliance is introduced and its implementation and evaluation are discussed. The framework interlinks functional components and establishes a behavioral sequence to operate the assistive system in three stages; action classification, verification, and execution. An action is classified based on identified human intent and verified through haptic and/or visual feedback before execution. The human intent is conveyed through …

Enhancing Microstructure, Composition Homogeneity, And Mechanical Properties In Laser Powder Bed Fused Metallic Alloys: Design, Fabrication, And Evaluation, Bahzad Farhang

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Over the past five decades, Nickel-based and Titanium-based alloys have become increasingly popular materials. As the manufacturing industry for these alloys has advanced, the demand for fabricating complex parts with enhanced mechanical properties at elevated temperatures has grown. Laser Powder Bed Fusion (LPBF), one of the most prevalent additive manufacturing techniques, has been employed successfully to produce these alloys. Nonetheless, there is still considerable effort being made to improve the microstructural, compositional, and mechanical properties of LPBF-processed components. In this study, we focused on adjusting the multi-scale microstructure and composition of LPBF-fabricated Nickel-based and Titanium-based alloys. The first objective …

Theoretical And Numerical Analysis Of Thermal Runaway Propagation In Li-Ion Battery Packs, Dhananjay Mishra

Mechanical and Aerospace Engineering Dissertations - Archive

Strategies to prevent or minimize propagation of thermal runaway in a pack of Li-ion cells are critically needed to ensure safe operation, storage and transportation. While significant literature already exists on thermal runaway simulations, several key questions of practical relevance have remained unaddressed. This work presents multi-mode heat transfer simulations to predict the onset and propagation of thermal runaway in a pack of cylindrical Li-ion cells. The impact of inter-cell gap and thermal properties of the interstitial material on onset and propagation of thermal runaway is studied. It is shown that high interstitial thermal conductivity promotes thermal runaway propagation. However, …

Steady State And Transient Analysis Of Heat Transfer In A Porous Fin With Radially Outwards Pressure-Driven Flow, Muhammad Mehdi Abbas

Mechanical and Aerospace Engineering Theses - Archive

Thermal management and energy storage problems often utilize extended surfaces, also known as fins for enhanced heat transfer. Today fins are used in a wide range of devices including but not limited to microelectronic components and large heat exchanger. Traditional fins as well as porous fins with flow orthogonal to fin direction have been subject of past research. There is very few academic literature available on porous fins with pressure driven flow along fin direction. While thermal conduction is usually the dominant mode of heat transfer in a solid fin, the use of porous fins that include advective thermal transport …

Development Of Vortex Box (Vbox) And Vortex Tip (Vtip) Filament Free-Wake Rotor Models, Casey Will Matsler

Mechanical and Aerospace Engineering Theses - Archive

Rotor models span from simple static and first order expressions to high fidelity, numerical computations and across the spectrum each model is good for different purposes. The use of models has improved with time and technological capability but choosing the right model for the task is important. A survey of rotor models is performed to identify a rotor model flexible enough for providing high to moderately high-fidelity results without significantly sacrificing computational time. The model chosen is intended to be for general purposes and applicable across a wide range of operating conditions. From the survey, a blade element rotor model …