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Experimental Characterization Of An Additively Manufactured Porous Gyroid Air-Cooled Heat Sink, Grant S. Resler Dec 2025

Experimental Characterization Of An Additively Manufactured Porous Gyroid Air-Cooled Heat Sink, Grant S. Resler

Mechanical Engineering Undergraduate Honors Theses

This paper presents the development of a ducted test facility designed to evaluate heat sinks efficiency at varying air velocities. This enables the evaluation of both heat transfer and pressure drop performance. These metrics are essential to the overall efficiency of heat sinks and help identify the optimal air velocity to achieve the desired thermal performance. A standard plate fin heat sink was used as a control for comparison to a novel heat sink. The specialized heat sink geometry was generated using nTop, a generative design software focused on additive manufacturing. This design was fabricated via Direct Metal Laser Sintering …


Effects Of Thermal Interface Materials On Thermal Conductivity Measurement Using A Modified Astm D5470 Thermal Resistance Tester, Chinmaya Joshi May 2025

Effects Of Thermal Interface Materials On Thermal Conductivity Measurement Using A Modified Astm D5470 Thermal Resistance Tester, Chinmaya Joshi

Mechanical Engineering Undergraduate Honors Theses

In this paper, we have investigated the effect of thermal interface materials (TIMs) on the accuracy and uncertainty of thermal conductivity measurements. A modified ASTM D5470 thermal resistance tester (TRT) is developed to measure the out-of-plane thermal conductivity of pyrolytic graphite (PG) and grade 2 titanium (TiG2) with and without TIMs. Compared to the ASTM D5470 standard, this modified design uses three thermocouples per side to support regressive analysis and explores the use of TIMs.s Nine PG samples and four TiG2 samples of varying thickness have been tested to obtain thermal resistance as a function of sample thickness. The steady-state …


Validating An Electronics Cooler Experiment And Optimizing Its Performance Using Ansys Icepak, Daniel V. Curl May 2025

Validating An Electronics Cooler Experiment And Optimizing Its Performance Using Ansys Icepak, Daniel V. Curl

Mechanical Engineering Undergraduate Honors Theses

Researchers at the University of Arkansas' Mechanical and Electrical Engineering Research Departments have designed and built a cold plate and substrate design for a 10 kV SiC MOSFET power module. Many variables define the design of the cold plate and substrate system and have quantifiable effects on the device’s performance. These variables include but are not limited to geometry and material selection of the fins and substrate. Manufacturing many test designs, running experiments, and comparing their performance is a time-consuming and expensive design optimization method that may be effective for some low-cost applications. Still, simulation is often a more cost-effective …


Introduction To Building Energy Modeling And Analysis Using Energyplus, Jackson C. Burnett May 2025

Introduction To Building Energy Modeling And Analysis Using Energyplus, Jackson C. Burnett

Mechanical Engineering Undergraduate Honors Theses

Retail stores are dynamic environments where human activities significantly influence energy consumption patterns, particularly affecting heating, ventilation, and air conditioning (HVAC) demands. Existing energy models, such as those developed using EnergyPlus, often rely on generalized assumptions about human occupancy and behavior, leading to discrepancies between predicted and actual energy usage. This research aimed to enhance the accuracy of energy modeling for retail stores by conducting a sensitivity analysis of occupancy using EnergyPlus simulations. The study investigated how variations in occupancy levels impact HVAC loads, cooling and heating demands, and overall energy use. Results showed that increasing occupancy leads to higher …


Development Of A Manifold Microchannel Heat Sink For The Electrification Of Aircraft, Joshua Mora Sanchez Dec 2024

Development Of A Manifold Microchannel Heat Sink For The Electrification Of Aircraft, Joshua Mora Sanchez

Mechanical Engineering Undergraduate Honors Theses

The miniaturization of microprocessors and power electronics is leading to critical thermal management challenges. For instance, the heat flux generated in modern computer chips is at the order of 100W/cm², which is well beyond the limit of air cooling. This high heat generation can cause a variety of thermal or mechanical failures in electronic devices. As such, there is a pressing need to devise effective cooling strategies for these microelectronic devices. Liquid cooling with microchannel heat sinks is a promising technology for high power loads. Nevertheless, traditional heat sinks with straight microchannels suffer from two critical challenges: high pressure drop …


Experimental And Numerical Investigation Of Air-Cooled Heat Sinks, Ethan Weems May 2024

Experimental And Numerical Investigation Of Air-Cooled Heat Sinks, Ethan Weems

Mechanical Engineering Undergraduate Honors Theses

Lightweight and affordable cooling capabilities are critical as the physical scale of electronics continues to decrease. Air-cooled heat sinks that dissipate heat from electronic components to the surrounding air are excellent candidates to fill this role. While plate-fin and pin-fin heat sinks have been implemented extensively for electronic cooling, recent advances in additive manufacturing enable the fabrication of more complex structures. In this undergraduate Honors thesis, a means by which to generate novel heat sink geometries is presented. To that end, an experimental characterization facility is developed to evaluate existing traditional heat sinks. The heat transfer performance of the heat …


Thermal Resistance Characterization Of High-Voltage Sic Power Module, Landon Lemmons Dec 2023

Thermal Resistance Characterization Of High-Voltage Sic Power Module, Landon Lemmons

Mechanical Engineering Undergraduate Honors Theses

Researchers within the University of Arkansas Electrical Engineering Research Department have embarked on a project aimed at enhancing the thermal performance of high-voltage power modules. To aid in the progress of this project, the design, and development of a thermal tester device are needed. The primary objective of this device is to determine the various thermal properties of high-voltage power modules that the electrical engineering department has developed. Additionally, the project aims to facilitate electrical loading tests on power modules and provide researchers with the means to calibrate the power module in terms of thermal load. This project also possesses …


A Systematic Study Into The Design And Utilization Of Burn Wire As A Means Of Tensioning And Releasing Spacecraft Mechanisms Through Applied Joule Heating, Chandler Dye May 2023

A Systematic Study Into The Design And Utilization Of Burn Wire As A Means Of Tensioning And Releasing Spacecraft Mechanisms Through Applied Joule Heating, Chandler Dye

Mechanical Engineering Undergraduate Honors Theses

The joule heating characteristics of Nichrome burn wires, often used as a thermal cutting device in mechanisms designed to fasten and release CubeSat deployables, are examined in the following thesis. Wires ranging from 0.125 inches to 2 inches long, and diameters of 30 Ga and 40 Ga, are investigated through analytical calculations and thermal simulations based on heat transfer due to joule heating, and through physical circuitry-based experiments. The temperature data is used to generate heating curves to predict the time it takes for Nichrome wires to fail under varying testing parameters. This research aims to catalog a series of …


Reynolds-Averaged Navier-Stokes Cfd Simulation Of High-Speed Boundary Layers, Michael Tullis May 2023

Reynolds-Averaged Navier-Stokes Cfd Simulation Of High-Speed Boundary Layers, Michael Tullis

Mechanical Engineering Undergraduate Honors Theses

This paper presents an investigation of Reynolds-averaged Navier-Stokes (RANS) turbulence models used in computational fluid dynamics (CFD) simulations of boundary layer flow and heat transfer in high Mach number flows. This study evaluates an industry standard RANS turbulence model (k-omega SST) and a recently proposed modification to that model (Danis and Durbin [1]), and quantifies the accuracy for predicting high Mach number boundary layer flow. The test cases were previously documented by Duan et al. (2018), who used direct numerical simulation (DNS) to calculate boundary layer flow of an ideal gas over a flat plate at freestream Mach numbers ranging …


Generative Designs Of Lightweight Air-Cooled Heat Exchangers, Connor Miller May 2022

Generative Designs Of Lightweight Air-Cooled Heat Exchangers, Connor Miller

Mechanical Engineering Undergraduate Honors Theses

The development of high-performance air-cooled heat exchangers is required to permit the rapid growth of vehicle and aircraft electrification. In electric vehicles and airliners, the motors and power electronics are integrated into a compact space, leading to unprecedently high power density. To achieve higher overall thermal efficiency, the heat exchangers must be extremely light while maintaining their heat transfer performance and mechanical robustness. Recently advances in 3D metal printing, e.g., direct metal laser sintering, and selective laser melting, have enabled the manufacturing of high-performance robust heat exchangers by eliminating thermal boundary resistance and ensuring a uniform thermal expansion coefficient. Nonetheless, …


Durability Of Non-Metallic Materials For Additively Manufactured Heat Spreader Fabrication, Rafael Estrella May 2022

Durability Of Non-Metallic Materials For Additively Manufactured Heat Spreader Fabrication, Rafael Estrella

Mechanical Engineering Undergraduate Honors Theses

Power electronics are necessary to convert power from DC sources for AC applications. As this technology trends toward smaller packaging for denser power loads, the increased electrical losses result in deleterious excess heat. Thermal management devices are required to prevent the effects of thermal runaway from shortening the longevity of these modules. Nonmetallic jet impingement heat spreaders provide several benefits in terms of weight and performance over conventional cold plates while not accentuating EMI from the switches in the power module; however, the polymer makeup of the materials previously used for fabricating these devices raises durability concerns under the high …


Transient Performance And Melt Front Characterization Of Phase Change Materials, Tyler Stamps May 2021

Transient Performance And Melt Front Characterization Of Phase Change Materials, Tyler Stamps

Mechanical Engineering Undergraduate Honors Theses

Thermal management systems are often over-designed for average use in order to handle spikes in heat generation, which increases the spatial and financial requirements. One way to mitigate this is via the use of phase change materials (PCMs) as thermal buffers and storage media. This material type exhibits excellent latent heat at the sacrifice of conductivity. The present paper examines the melt front behavior of a common solid to liquid PCM, paraffin, experimentally and numerically. The experimental scenario was a block of PCM with a constant temperature heat flux introduced on one end and a constant temperature cold boundary condition …


Algorithm Development Of Topology Optimization For Pcm Based Heat Sinks, Diego L. De Los Reyes May 2021

Algorithm Development Of Topology Optimization For Pcm Based Heat Sinks, Diego L. De Los Reyes

Mechanical Engineering Undergraduate Honors Theses

With the inherent usage of the computer when dealing with additive manufacturing, it only makes sense to use that higher computing power through simulation and iterative design to use the mathematical concept of topology and optimize the kind of geometry and shapes to be produced for a certain application, especially thermal ones since most 3D printing applications focus on purely the mechanical. To determine what the shape will be, an objective function of how much heat can be dispersed from a hypothetical heat source, assumed to be a type of electronic device, is maximized while being constrained by other variables, …


Thermal Testing And Characterization Of Nanoparticles Synthesized For Biological Treatment, Tonie Butler May 2021

Thermal Testing And Characterization Of Nanoparticles Synthesized For Biological Treatment, Tonie Butler

Mechanical Engineering Undergraduate Honors Theses

The overall goal of this research project is to synthesize iron core, silica capped nanoparticles that, when they are exposed to a particular magnetic field, will react by increasing in temperature and emitting substantial thermal output. They will be injected into the human body for biological benefit by targeted thermal radiation. Once in the human body, ideally, they will be able to target a specific area, and then a magnetic field will be applied to induce thermal output through the process of hyperthermia. As the nanoparticles emit heat, they will mimic the natural bodily behavior seen by way of hyperthermia, …


Enhancement Of Phase Change Material Sorbitol By Nanoparticle Inclusion For Improving Thermal Energy Storage Capabilities, Joshua Kasitz May 2020

Enhancement Of Phase Change Material Sorbitol By Nanoparticle Inclusion For Improving Thermal Energy Storage Capabilities, Joshua Kasitz

Mechanical Engineering Undergraduate Honors Theses

Thermal management of electronic devices has become an increasingly vital field of study with the rapid miniaturization of many key electrical components. With the significant improvement of semiconductor manufacturing and intensified focus on interconnects, electronic devices have decreased in size at an incredible rate. Decreasing spatial requirements is essential to improving device capabilities as the electronic system is able to incorporate more components. Currently, electronic systems are drastically limited by the capabilities of their cooling mechanisms. Smaller devices lead to large increases in the energy density of the system and require more powerful cooling systems to maintain proper component operating …


Optimization Of The Practice Of Slow Cooling Steel Bars: A Redesign And Modernization Of Materials, Eryn Johnston Dec 2018

Optimization Of The Practice Of Slow Cooling Steel Bars: A Redesign And Modernization Of Materials, Eryn Johnston

Mechanical Engineering Undergraduate Honors Theses

Throughout the process of steel making, certain grades of steel are a higher risk for defects caused by the inability to quickly diffuse hydrogen through the steel when cooled to room temperature at a normal rate based on the ambient air temperature. To reduce the hydrogen flaking defects that are caused due to hydrogen entrapment in the steel, the process of slow cooling is utilized. This process reduces the cooling rate of steel bars by keeping them at a higher temperature for extended periods and in turn gives the hydrogen a chance to fully dissipate from the steel. In many …