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Heat Transfer Vest, Nicholas Forsgaard 2018 Central Washington University

Heat Transfer Vest, Nicholas Forsgaard

All Undergraduate Projects

The purpose of this report is to document the progression of the authors senior project. . The of that project was the research of Liquid Cooled Garment (LCG) technology, the generation of a novel LCG prototype and the testing of that prototype relative to a commercial benchmark. As such, this report is a complete narrative of the of these tasks, their execution and the underlying assumptions and commentary. The motivation for this report is to satisfy the capstone requirements of the MET program at CWU by documenting the Senior Project and its subordinate tasks. First, the student designed a LCG system ...


Design And Validation Of An Experimental Setup To Study Single Phase Heat Transfer Enhancement Of Femtosecond Laser Processed Metallic Surfaces, Sarah Jane Wallis 2017 University of Nebraska-Lincoln

Design And Validation Of An Experimental Setup To Study Single Phase Heat Transfer Enhancement Of Femtosecond Laser Processed Metallic Surfaces, Sarah Jane Wallis

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

In the present work, a single phase flow heat transfer experimental loop was designed with the intention of studying the effects of femtosecond laser surface processing (FLSP) on metallic surfaces with the specific goal of enhancing heat transfer in compact heat exchangers currently in use by NASA. This experimental setup went through two major design iterations which are detailed in this thesis. The first iteration consisted of a counterflow fluid-to-fluid heat exchanger, which measured overall heat transfer coefficients and pressure drops, where the overall heat transfer coefficient is defined in terms of the total thermal resistance to heat transfer between ...


The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet 2017 The University of Western Ontario

The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet

Electronic Thesis and Dissertation Repository

The motivation of this thesis is the development of simple microscopic-scale model (representative elemental volume; REV) that can be used to conduct flow and heat transfer simulations from which closure coefficients can be established for the volume-averaged transport equations for porous media (packed bed). The thesis provides a brief introduction to the computational technique adopted for the geometric generation of the REV (YADE), followed by a parametric study undertaken to reveal the minimum number of particles inside the REV that are required to mimic the appropriate physics. Additional analysis was conducted with the goal of determining the influence of deviation ...


The Onset Of Convection In Rarefied Gases, Md Asif Zobaer 2017 The University of Western Ontario

The Onset Of Convection In Rarefied Gases, Md Asif Zobaer

Electronic Thesis and Dissertation Repository

The onset of convection in the Rayleigh-Bénard problem for a monatomic rarefied gas at small Knudsen number has been investigated. Compressibility-induced density variations have been considered without imposing any restriction on the magnitude of temperature difference. A linear temporal stability analysis has been conducted for a compressible slip-flow model considering a Maxwellian gas and the dispersion relation is calculated using a Chebyshev collocation method. A neutral stability curve obtained in the Froude-Knudsen number plane marks transition to convection from a pure conduction state. The critical wave number observed for the onset of convection is in good agreement with the existing ...


Numerical Simulations Of Transcritical Natural Convection, Ruiwen Wei, Carlo Scalo, Mario Tindaro Migliorino, Kukjin Kim, Jean-Pierre Hickey 2017 Purdue University

Numerical Simulations Of Transcritical Natural Convection, Ruiwen Wei, Carlo Scalo, Mario Tindaro Migliorino, Kukjin Kim, Jean-Pierre Hickey

The Summer Undergraduate Research Fellowship (SURF) Symposium

In modern engineering applications, system overheating is a key issue that needs to be solved with efficient and reliable cooling technologies. Among the possible mechanisms that these are based on, natural convection cooling is one of the most frequently employed, with applications ranging from cooling of computer micro-components to large nuclear reactors. While many studies have been performed on natural convection employing supercritical or subcritical fluids, little attention has been given to fluids in their transcritical regime. The latter has the potential to yield high performances while avoiding detrimental effects of two-phase systems (e.g. cavitation). In the present study ...


Modal Phonon Transport Across Interfaces By Non-Equilibrium Molecular Dynamics Simulation, Yang Zhong, Tianli Feng, Xiulin Ruan 2017 Purdue University

Modal Phonon Transport Across Interfaces By Non-Equilibrium Molecular Dynamics Simulation, Yang Zhong, Tianli Feng, Xiulin Ruan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Phonons represent the quantization of lattice vibration, responsible for heat transfer in semiconductors and dielectrics. Phonon heat conduction across interfaces is crucially important for the thermal management of real-life devices such as smartphones, electric vehicles, and satellites. Although recent studies have broadly investigated spectral phonon contribution to lattice thermal conductivity, the mechanism of phonon modal transport across interfaces is still not well-understood. Previous models, including the acoustic mismatch model (AMM) and diffuse mismatch model (DMM), only consider elastic process while neglecting inelastic phonon contributions. Herein, we employ spectral Non-Equilibrium Molecular Dynamics Simulation (NEMD) to probe the temperature and heat flux ...


Secondary Atomization: Drop Breakup In A Continuous Air Jet, Grant S. Sondgeroth, Longchao Yao, Catriona M.L. White, Daniel R. Guildenbecher, Jun Chen, Paul E. Sojka 2017 Purdue University

Secondary Atomization: Drop Breakup In A Continuous Air Jet, Grant S. Sondgeroth, Longchao Yao, Catriona M.L. White, Daniel R. Guildenbecher, Jun Chen, Paul E. Sojka

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding drop breakup will optimize aircraft engine performance, reduce agro-chemical overspray, and improve pharmaceutical tablet efficacy. Large fuel fragments in engines lead to lowered fuel economy and higher pollutant emissions, while small drops yield more agro-spray drift into surrounding residential and environmental zones. Better pharmaceutical tablets will improve drug uptake and patient comfort.

Engineers and scientists are currently unable to predict the number, size, and velocity of fragments formed during important drop breakup processes. Therefore, we are required to measure these quantities. We use digital inline holography (DIH) to record three-dimensional diameter and position data for fragments formed during multi-mode ...


Burning Surface Temperature Measurements Of Propellants And Explosives Using Phosphor Thermography, Ethan A. Whitaker, Alex D. Casey, Steven F. Son 2017 Purdue University

Burning Surface Temperature Measurements Of Propellants And Explosives Using Phosphor Thermography, Ethan A. Whitaker, Alex D. Casey, Steven F. Son

The Summer Undergraduate Research Fellowship (SURF) Symposium

Temperature measurements of propellants and explosives are necessary to create accurate models which lead to better understanding of energetic characteristics such as burning rate. Previous attempts at measuring surface temperatures of burning propellants and explosives using thermocouples have suffered from large uncertainty. Thermographic phosphor thermography employs ceramic powders called phosphors whose spectroscopic properties can be used to remotely and nearly non-intrusively measure temperature. Improved methods were developed for application of this technique to energetic materials to yield more accurate, two-dimensional temperature measurements. In this study, zinc oxide doped with gallium, a thermographic phosphor, was mixed into HMX and RDX powder ...


Spectral Phonon Relaxation Time Calculation Tool Based On Molecular Dynamics, Divya Chalise, Tianli Feng, Xiulin Ruan 2017 University of Texas at Arlington

Spectral Phonon Relaxation Time Calculation Tool Based On Molecular Dynamics, Divya Chalise, Tianli Feng, Xiulin Ruan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermal conductivity is an important material property which affects the performance of a wide range of devices from thermoelectrics to nanoelectronics. Information about phonon vibration modes and phonon relaxation time gives significant insight into understanding and engineering material’s thermal conductivity. Although different theoretical models have been developed for studying phonon modes and relaxation time, extensive knowledge of lattice dynamics and molecular dynamics is required to compute phonon modal frequencies and relaxation times. Therefore, a computational tool which can take simple inputs to calculate phonon mode frequencies and relaxation time will be beneficial. Through this research work, such computational tool ...


Thermoelectric System Modeling And Design, Buddhima Pasindu Gamarachchi 2017 Boise State University

Thermoelectric System Modeling And Design, Buddhima Pasindu Gamarachchi

Boise State University Theses and Dissertations

Thermoelectric generators (TEGs) convert heat to electricity by way of the Seebeck effect. TEGs have no moving parts and are environmentally friendly and can be implemented with systems to recover waste heat. This work examines complete thermoelectric systems, which include the (TEG) and heat exchangers or heat sinks attached to the hot and cold sides of the TEG to maintain the required temperature difference across the TEG. A 1-D steady state model is developed to predict the performance of a TEG given the required temperatures and device dimensions. The model is first validated using a 3-D model and then is ...


Us Patent 9,702,573: Nested Heat Transfer System, Sanza Kazadi 2017 Selected Works

Us Patent 9,702,573: Nested Heat Transfer System, Sanza Kazadi

Sanza Kazadi

A novel nested heat transfer system comprises a plurality of chained enhanced entrochemical cells with nested structures. Each enhanced entrochemical cell includes a first chamber containing desiccant, or a higher concentration solution, and a second chamber containing refrigerant,   or   a   lower   concentration   solution.   Preferably,   the   first   chamber   and   the   second   chamber   are   connected   by   a   conduit.  Furthermore,   a   smaller   chamber   in   an   enhanced   entrochemical   cell   is   encapsulated   by   a   larger   chamber   in   an   adjacent   enhanced entrochemical cell, thus forming a nested structure between the two enhanced entrochemical cells. A chain of enhanced entrochemical cells with a plurality of such nested ...


A Wood-Powered Lawn Mower: Separating The Rules Of Thumb From Engineering Design, William White 2017 Western Kentucky University

A Wood-Powered Lawn Mower: Separating The Rules Of Thumb From Engineering Design, William White

Honors College Capstone Experience/Thesis Projects

Biomass gasification, the thermal process of exracting combustible gasses from organic matter, is an established procedure that has been used for many years to provide fuel in various applications. It is a potential source of renewable fuel and has proven useful as a crisis energy source. This thesis investigates the primary engineering science principles involved in gasifier-engine system design. It arises from and supplements a WKU mechanical engineering senior project. The senior project has developed a wood gasification system designed to power a riding lawn mower. The thesis reiews theory-based design and separates it from informal hit and miss approaches ...


Inspection And Model Based Inversion Of Highly Curved Composite Surfaces With Flash Thermography, Bryan E. Schiefelbein, Stephen D. Holland 2017 Iowa State University

Inspection And Model Based Inversion Of Highly Curved Composite Surfaces With Flash Thermography, Bryan E. Schiefelbein, Stephen D. Holland

Stephen D. Holland

With the development of advanced aircraft structures and stringent mechanical requirements, robust and reliable inspection methods are needed to ensure safe operation and maximum utilization of the equipment [1]. Aircraft composite parts can exhibit complex geometries and tight curvature, such as leading edges and chines. These curved structures are difficult to inspect for defects, especially where the local curvature is high [2–4]. Pulsed thermography has the potential for rapid inspection of large areas, making it attractive for depot or field inspection of large aircraft parts. When imaging areas of high curvature, there are a number of confounding factors, including ...


Model-Based Inversion For Flash Thermography, Stephen D. Holland, Brian Schiefelbein 2017 Iowa State University

Model-Based Inversion For Flash Thermography, Stephen D. Holland, Brian Schiefelbein

Stephen D. Holland

The thermal image sequences from thermography experiments are blurred by lateral diffusion and therefore hard to interpret. The widely used one-dimensional heat flow model provides a robust interpretation of thickness or delamination from “break time” where lateral diffusion is significant, but is less effective otherwise. As a result, it remains quite common to interpret defects by contrast from the surrounding “acreage” rather than by the intrinsic properties of the defect signal itself. In this paper, we present an approach for model-based inversion of flash thermography image sequences that attempts to approximately reconstruct the flow or back-surface geometry from the thermal ...


Simple Tester For Measuring Lateral Thermal Diffusivities In Composites, Stephen D. Holland, Elizabeth Gregory, Daniel Romero 2017 Iowa State University

Simple Tester For Measuring Lateral Thermal Diffusivities In Composites, Stephen D. Holland, Elizabeth Gregory, Daniel Romero

Stephen D. Holland

Model-based analysis and inversion of thermography data relies on knowledge of thermal diffusivities. Through-thickness diffusivity is readily measured using the flash method [1]. In composite materials, lateral diffusivities may be drastically different from the through-thickness values, but there is no comparable simple and standard approach for measuring those lateral thermal diffusivities. Welch, Heath, and Winfree [2] proposed a technique based on laser line pulse excitation, but that approach requires a reasonably powerful laser and thermal camera with the concomitant costs and safety requirements. In this presentation, we show a simple and low cost (but not entirely nondestructive) system and method ...


Adhesion Hysteresis And Its Role In Vibrothermography Crack Heating, Bryan E. Schiefelbein, Tyler Lesthaeghe, Ashraf F. Bastawros, Stephen D. Holland 2017 Iowa State University

Adhesion Hysteresis And Its Role In Vibrothermography Crack Heating, Bryan E. Schiefelbein, Tyler Lesthaeghe, Ashraf F. Bastawros, Stephen D. Holland

Stephen D. Holland

Vibrothermography is an NDE inspection which uses vibration to stimulate surface cracks and measure the resultant heat generation. For years, the accepted assumption has been that heat generation in Vibrothermography NDE is due to friction between opposing crack surfaces [1–3]. A frictional mechanism suggests that crack surfaces in sliding shear would generate heat, whereas crack surfaces coming into and out of contact in an opening-closing mode would not, or would generate much less. But cracks heat easily in opening/closing mode and experimental evidence [4] is not consistent with the prediction that heat generation for shear vibration should be ...


Turbulent Combustion Of Polydisperse Evaporating Sprays With Droplet Crossing: Eulerian Modeling And Validation In The Infinite Knudsen Limit, S. de Chaisemartin, L. Freret, D. Kah, F. Laurent, Rodney O. Fox, J. Reveillon, M. Massot 2017 Ecole Centrale Paris

Turbulent Combustion Of Polydisperse Evaporating Sprays With Droplet Crossing: Eulerian Modeling And Validation In The Infinite Knudsen Limit, S. De Chaisemartin, L. Freret, D. Kah, F. Laurent, Rodney O. Fox, J. Reveillon, M. Massot

Rodney O. Fox

The accurate simulation of the dynamics of polydisperse evaporating sprays in unsteady gaseous flows with large-scale vortical structures is both a crucial issue for industrial applications and a challenge for modeling and scientific computing. The difficulties encountered by the usual Lagrangian approaches make the use of Eulerian models attractive, aiming at a lower cost and an easier coupling with the carrier gaseous phase. Among these models, the multi-fluid model allows for a detailed description of the polydispersity and size-velocity correlations for droplets of various sizes. The purpose of the present study is twofold. First, we extend the multi-fluid model in ...


Conditional-Moment Closure With Differential Diffusion For Soot Evolution In Fire, J. C. Hewson, A. J. Ricks, S. R. Tieszen, A R. Kerstein, Rodney O. Fox 2017 Sandia National Laboratories

Conditional-Moment Closure With Differential Diffusion For Soot Evolution In Fire, J. C. Hewson, A. J. Ricks, S. R. Tieszen, A R. Kerstein, Rodney O. Fox

Rodney O. Fox

The conditional-moment closure (CMC) equation for the evolution of a large Lewis number scalar, soot, is derived starting from the joint probability density function (pdf) equation for the gas-phase mixture fraction, ξ g , and the soot mass fraction, Y s . Unlike previous approaches starting with the joint pdf, the residual terms that result from the typical closure models were retained. A new formulation of the one-dimensional turbulence (ODT) model suitable for spatially evolving flows with buoyant acceleration and radiative transport in participating media was employed to carry out simulations of a prototypical ethene fire. The resulting ODT evolution of ξ ...


Improved Method Of Co2 Laser Cutting Of Aluminum Nitride, Raathai Molian, Pranav Shrotriya, Pal Molian 2017 Iowa State University

Improved Method Of Co2 Laser Cutting Of Aluminum Nitride, Raathai Molian, Pranav Shrotriya, Pal Molian

Pranav Shrotriya

The traditional “evaporation∕melt and blow” mechanism of CO2 laser cutting of aluminum nitride (AlN) chip carriers and heat sinks suffers from energy losses due to its high thermal conductivity, formation of dross, decomposition to aluminum, and uncontrolled thermal cracking. In order to overcome these limitations, a thermochemical method that uses a defocused laser beam to melt a thin layer of AlN surface in oxygen environment was utilized. Subsequent solidification of the melt layer generated shrinkage and thermal gradient stresses that, in turn, created a crack along the middle path of laser beam and caused material separation through unstable crack ...


Additive Manufacturing For Post-Processing, Nathan D. Goodwin, Andrew Furmidge 2017 California Polytechnic State University, San Luis Obispo

Additive Manufacturing For Post-Processing, Nathan D. Goodwin, Andrew Furmidge

Mechanical Engineering

No abstract provided.


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