Engineering Commons^™

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 …

Cool Thermal Energy Storage: Water And Ice To Alternative Phase Change Materials, Sandra K. S. Boetcher

Publications

Cool thermal energy storage has a long history dating back to ancient times with modern developments beginning in the mid-nineteenth century where blocks of ice were cut from frozen lakes for cooling applications. Today, the prevalent mode of thermal energy storage is the utilization of ice tanks in commercial buildings for peak shaving and load shifting. In this chapter, a summary of different types of water/ice thermal energy storage systems is provided; an overview of alternative phase change materials for use in cool thermal energy storage is given; and alternative phase change material thermal energy systems, their implementation, challenges, and …

Refrigeration & Pressure Circuits For The Test Apparatus On Triaxial Properties Of Polymer Foams At Arctic Temperatures, Nathaniel Ackerman

Williams Honors College, Honors Research Projects

The objective of this project is to modify the previous testing apparatus used by Dr. M. Hoo Fatt for exploration of Crushing Behavior of Polymer Foams in Sandwich Structures Operating in Arctic Regions commissioned by the Office of Naval Research and performed under the University of Akron’s Mechanical Engineering testing facilities. To do this, it is required to design a system capable of operating at a constant temperature during a testing cycle, reaching down to -60⁰C. This apparatus must also be compatible with prior equipment, facilities, persons, samples, and media.

Primarily, a copper-tube refrigeration coil design was considered to lead …

Liquid-Vapor Distributions In Evacuated Small Diameter Channels For Improved Accuracy Of Initial Conditions In Modeling Of Oscillating Heat Pipes, Travis Mayberry

Mechanical Engineering Research Theses and Dissertations

Oscillating heat pipes, also known as pulsating heat pipes, are increasingly becoming a preferred high-performance thermal ground plane in a variety of heat spreading applications due to a number of advantages over traditional copper-water wicked heat pipes, including their lighter weight, thinner profiles, simpler fabrication, and greater variety of material and working fluid options. A major barrier to even wider adoption, however, is the lack of comprehensive analytical models to simulate their performance. A key input to first principles models simulating the fundamental physics of the devices is the initial condition of liquid and vapor segment lengths and their distribution …

Geometrically Complex Planar Heat Exchangers, Derli Dias Do Amaral Junior, Jose Lage

Mechanical Engineering Research Theses and Dissertations

In this study, geometrically complex planar heat exchangers, designed in line with the Constructal Law and operating at steady-state, are investigated numerically. The work is divided into two parts, one focusing on diffusion heat transfer in a rectangular plane and another on conjugate diffusion-convection heat transfer in a circular plane heat exchanger.

In the first part, a heat generating rectangular solid volume made of a low conductivity material is cooled through a small, isothermal side-section of the domain. The diffusion cooling process is improved by distributing within the heat generating material a fixed amount of a high conductivity material. The …

Pulse Decay Thermal Conductivity Device, Matthew Schrenk

All Undergraduate Projects

Currently, there are several ways in which thermal conductivity can be calculated or assessed on a given material. However, with each method of testing comes potential limitations such as size, material state, complexity, and time. The goal of this study was to develop a pulse heated thermistor that would reduce all four limitations, thus provide precise and timely results regardless of the material state and size. A thermistor is resistor which changes resistance in accordance to temperature. To achieve the design, heat transfer and electrical methods were applied. As with all resistors, heat is dissipated across the element and released …

Modeling, Simulation, And Testing Of Sweeping Convection, Amir Kiaee

Mechanical Engineering Research Theses and Dissertations

In this study, the new convection heat transfer concept of sweeping convection, using large particles flowing with a fluid in a channel, is considered. This novel concept is inspired by the gas exchange process in alveolar capillaries, where red blood cells (RBCs) flow with blood plasma, yielding very high gas transfer efficiency. An important characteristic of alveolar capillary blood flow, believed to be related to the high efficiency of the lungs, is the snug fitting of the RBCs into the capillaries. This tight fitting sets the RBCs (particles) acting like pistons as they flow downstream with the plasma (fluid), facilitating …

Graphs And Cad: Analyzing The Experience Of A Mechanical Engineering Intern, Matthew Des Biens

Celebration of Learning

A reflection on the experiences of a mechanical engineering intern at Bergstrom Inc., this presentation, by Senior Matt Des Biens, will discuss what it was like working for a manufacturing and design company making HVAC units for large customers across the world. The highlights will be on the projects he worked on, the things that he learned, and his views on working for the company as a whole.