Fluid Analysis In Solar Heat Pipes, Ben Krumholz, Michael Agavo, William Dundon

Mechanical Engineering

Evacuated tube solar collectors are efficient systems that use heat pipes to facilitate heat transfer. They use incoming solar radiation to heat water. Professor Mason Medizade tasked the team with choosing a component of the system to research and test its influence on system performance. The team investigated the working fluid that runs through the heat pipes. Distilled water, acetone, and ethanol at a range of fill volumes form 1 mL to 11 mL were tested. The team's goal was to find a volume for each fluid to maximize performance of the system. Performance was defined as average temperature rise …

A Study Of Constant Voltage Anemometry Frequency Response, Alex D. Powers

Master's Theses

The development of the constant voltage anemometer (CVA) for the boundary layer data system (BLDS) has been motivated by a need for the explicit autonomous measurement of velocity fluctuations in the boundary layer. The frequency response of a sensor operated by CVA has been studied analytically and experimentally. The thermal lag of the sensor is quantified by a time constant, M_CVA. When the time constant is decreased, the half-amplitude cut-off frequency, f_CVA, is increased, thereby decreasing the amount of attenuation during measurements. In this thesis, three main approaches have been outlined in theory and tested experimentally …

Heat Of Fusion Of Primary Alcohol Confined In Nanopores, Harrisonn Griffin

Honors Theses

Melting behavior of physically confined 1-decanol in nano porous silica was probed using a Differential Scanning Calorimeter (DSC). In agreement with the Gibbs-Thomson prediction, we observe that the melting temperature of the confined 1-decanol scales inversely with the physical size of the pores. Contrary to the assumption used in developing the Gibbs-Thomson equation, however, the apparent heat of fusion decreases as the pore size decreases. Previously, several models have been proposed where interfacial layers of molecules do not participate in the phase transition and thereby would not contribute to the heat of fusion. While these could reconcile the seeming contradiction, …

A Numerical Study Of Compressible Lid Driven Cavity Flow With A Moving Boundary, Amer Hussain

University of New Orleans Theses and Dissertations

A two-dimensional (2-D), mathematical model is adopted to investigate the development of circulation patterns for compressible, laminar, and shear driven flow inside a rectangular cavity. The bottom of the cavity is free to move at a specified speed and the aspect ratio of the cavity is changed from 1.0 to 1.5. The vertical sides and the bottom of the cavity are assumed insulated. The cavity is filled with a compressible fluid with Prandtl number, Pr =1. The governing equations are solved numerically using the commercial Computational Fluid Dynamics (CFD) package ANSYS FLUENT 2015 and compared with the results for the …

Effect Of Non-Uniform Air-Side Velocity Distribution On Heat Transfer Model Predictions For Microchannel Condenser., Zachary Chapin

Electronic Theses and Dissertations

This is a study of the effects on heat transfer capacity predictions of microchannel condensers when airflow is maldistributed due to the shape of the condenser. The three shapes investigated in this study are flat, U-shape and roll. Each coil was tested in a water calorimeter and those results were compared to the model prediction. The model prediction was calculated using CoilDesigner™ modeling software with standard correlations. Using the uniform airflow assumption, the model over predicted the heat capacity measured in the calorimeter by 5-11% depending on the coil and inlet conditions. The local airflow velocity was measured using a …

Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby

Masters Theses

Atmospheric entry studies typically look closely at the peak heating rate that a body encounters during its trajectory. This is an extremely important phenomenon to study because it allows engineers to determine if a trajectory is possible with given materials and craft design specifications. It also allows designers to choose what type of method will be used for mitigating the enormous heat fluxes during entry. In general, it is accepted that during the super-sonic flight regime the body will continue to be heated and an ablative heat shield often is used to deal with these heating processes. The theory outlined …

Study To Reduce Peak Electrical Demand Charges For The John C. Hodges Library, Jared Thomas Carpenter, Isaac Michael Robinette, Matthew Joeseph Conrad, Daniel Matthew Whaley, William A. Miller

Chancellor’s Honors Program Projects

No abstract provided.

Leidenfrost Energy Barriers, James Peck, Anton Hassebrook, Craig Zuhlke, Troy P. Anderson, Dennis R. Alexander, George Gogos, Sidy Ndao

UCARE Research Products

In this work, an “Energy Barrier” was created to control the motion of Leidenfrost droplets. This barrier was created by functionalizing a portion of a mirror-polished stainless steel 304 surface with Femtosecond Laser Surface Processing (FLSP). FLSP results in superhydrophilic, hierarchical, micro- and nanostructures which are highly wetting and thus have an increased Leidenfrost temperature. Water droplets in the film boiling state were deposited, and propelled by gravity towards the Energy Barrier interface. Room temperature droplets were deposited over a range of surface temperatures beginning with the Leidenfrost temperature of mirror-polished stainless steel 304 and culminating at the Leidenfrost temperature …

Method For Determining Time-Resolved Heat Transfer Coefficient And Adiabatic Effectiveness Waveforms With Unsteady Film Cooling, James L. Rutledge, Jonathan F. Mccall

AFIT Patents

A new method for determining heat transfer coefficient (h) and adiabatic effectiveness (η) waveforms h(t) and η(t) from a single test uses a novel inverse heat transfer methodology to use surface temperature histories obtained using prior art approaches to approximate the h(t) and η(t) waveforms. The method best curve fits the data to a pair of truncated Fourier series.

Numerical Investigation Of Full Scale Thunderstorm Downbursts: A Parametric Study And Comparison To Meteorological Model, Christopher Oreskovic

Electronic Thesis and Dissertation Repository

A series of Large Eddy Simulations using an atmospheric meteorological cloud model have been used to investigate the important geometric and thermal parameters that influence a thunderstorm downburst outflow, as it pertains specifically to the idealized cooling source model. A separate set of Large Eddy Simulations make use of the same idealized cooling source model, in a realistic atmospheric base state using real field sounding data, in an attempt to make a quantifiable comparison to a downburst from a full cloud simulation. Randomness has been added to the cooling source forcing function to mimic the thermal variation in a real …

Heating Element Including Carbon Nanotube (Cnt) Layer, Santhosh Kumar Loganathan, Virginie Rollin, Daewon Kim

Publications

Apparatus , materials , and techniques and techniques herein can include providing a deposited layer comprising a com posite material including carbon nanotubes ( CNTs ) . Accord ing to various examples , the composite can be applied to a substrate such as using a solution containing CNTs and other constituents such as sulfur . The solution can be spray applied to a substrate , or spin - coated upon a substrate , such as to provide a uniform , conductive , and optically - transpar ent film layer . In one application , such a film layer can be …

A Model For Complex Heat And Mass Transport Involving Porous Media With Related Applications, Furqan A. Khan

Electronic Thesis and Dissertation Repository

Heat and mass transfer involving porous media is prevalent in, for example, air-conditioning, drying, food storage, and chemical processing. Such applications require non-equilibrium heat and mass (or moisture) transfer modeling inside porous media in conjugate fluid/porous/solid framework. Moreover, modeling of turbulence and turbulent heat and mass transfer becomes essential for many applications. A comprehensive literature review shows a scarcity of models having such capabilities. In this respect, the objectives of the present thesis are to: i) develop a formulation that simulates non-equilibrium heat and mass transfer in conjugate fluid/porous/solid framework, ii) demonstrate the capabilities of the developed formulation by simulating …

Modeling Of Methane Tank Depressurization In Cold Weather, Brittney Bridger-Burton, Kevin D. Cole

UCARE Research Products

Non-metallic tanks are used in industry to store and transfer gasses such as methane. As the tanks are emptied, the properties of the gas change, causing heat transfer with the tank wall. When emptied while at low temperatures, liquid condensation can form and the tank lining can reach a critically low temperature, causing fracture to the tank wall. In this study, the emptying of methane in cold weather conditions from a non-metallic tank was modelled using Aspen Tech Software. A full tank of methane, at 250 bar and 288 K, was cooled to the following starting temperatures: 263, 253, 243, …

Application Of A Multi-Zone Model For The Prediction Of Species Concentrations In Rapid Compression Machine Experiments, David Wilson

Master's Theses (2009 -)

Accurate chemical kinetic models, which predict species evolution and heat release rates in chemically reactive systems, are essential for further advancements in fuel and combustion technology. An experimental facility that is widely used for evaluating the accuracy of kinetic models is a rapid compression machine (RCM), which creates a well-defined reaction environment by compressing a reactive mixture inside a chamber. Generally, RCM experiments are conducted in order to obtain ignition delay data. However, chemical speciation data provides greater insight into reaction pathways, and is therefore a more rigorous benchmark for validating kinetic models. In order for a chemical kinetic model …

Notes On Contributions To The Science Of Rare Earth Element Enrichment In Coal And Coal Combustion Byproducts, James C. Hower, Evan J. Granite, David B. Mayfield, Ari S. Lewis, Robert B. Finkelman

Center for Applied Energy Research Faculty and Staff Publications

Coal and coal combustion byproducts can have significant concentrations of lanthanides (rare earth elements). Rare earths are vital in the production of modern electronics and optics, among other uses. Enrichment in coals may have been a function of a number of processes, with contributions from volcanic ash falls being among the most significant mechanisms. In this paper, we discuss some of the important coal-based deposits in China and the US and critique classification systems used to evaluate the relative value of the rare earth concentrations and the distribution of the elements within the coals and coal combustion byproducts.

Application Of Natural Convection For Photovoltaic Cooling And Photocatalytic Disinfection, Usman J. Rajput

Electronic Thesis and Dissertation Repository

Two investigations for improving renewable technologies are engaged. First is the examination of the enhancement of heat transfer at the rear of a hot photovoltaic panel by natural convection using various configurations and the other is analyzing a new photocatalytic collector for water heating and cleaning. A 20 Watt polycrystalline panel is exposed to indoor simulated solar light, under constant ambient temperature and stagnant wind conditions. Three configurations are considered: a partial heat sink, a water cavity and a water channel. The experimentally obtained convective heat transfer coefficients are 4.4 W•m^-2•K^-1 at the rear of the bare …

Procesy Cieplne I Aparaty (Lab), Wojciech M. Budzianowski

Wojciech Budzianowski

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Economical Retrofit System To Reduce Cooking Emissions In Third World Dwellings, Jonathan Vanzummeren, Tyler Sturgeon, Ben Dalessandro

Williams Honors College, Honors Research Projects

Abstract:

The purpose of this document is to propose and demonstrate the feasibility and effectiveness of substituting an open flame biomass cooking process with a closed system with the capabilities of sustaining an adequate fire. Clay ovens or “chulhas” are the traditional piece of cooking equipment used in poorer areas of the world. They are often built inside cramped one-room housing units with little or no ventilation. The emissions released from burning fuel sources such as wood, coal, or animal waste bring with them detrimental and often fatal health problems and results in approximately 1.3 million deaths per year.

The …

Effect Of Spalled Particles Thermal Degradation On A Hypersonic Flow Field Environment, Raghava S. C. Davuluri, Huaibao Zhang, Alexandre Martin

Mechanical Engineering Faculty Publications

Two-way coupling is performed between a spallation code and a hypersonic aerothermodynamics CFD solver to evaluate the effect of spalled particles on the flow field. Time accurate solutions are computed in argon and air flow fields. A single particle simulations and multiple particles simulations are performed and studied. The results show that the carbon vapor released by spalled particles tend to change the composition of the flow field, particularly the upstream region of the shock.

Solar Thermal Collector, Hazel Tickner, Tyson Nakamura

All Undergraduate Projects

During the course of this project, a solar thermal collector and supporting stand were designed and manufactured to be used during Mechanical Engineering Technology labs. Students will be able to use the collector to heat water, with the sun being the only heat source. The collector was designed by calculating surface area limitations, estimated solar input, and desired efficiency, to find the required water flow rate. From there, the necessary pipe lengths and diameters were determined, and the solar thermal collector was constructed. Two pipe paths were manufactured: a curved path, and a manifold path. Students will be able to …

Performance Evaluation Of Palm Oil-Based Biodiesel Combustion In An Oil Burner, Abdolsaeid Ganjehkaviri, Mohammad Nazri Mohd Jaafar, Seyed Ehsan Hosseini, Anas Basri Musthafa

Faculty Publications - Mechanical Engineering

This paper presents an experimental investigation of the combustion characteristics of palm methyl ester (PME), also known as palm oil-based biodiesel, in an oil burner system. The performance of conventional diesel fuel (CDF) and various percentages of diesel blended with palm oil-based biodiesel is also studied to evaluate their performance. The performance of the various fuels is evaluated based on the temperature profile of the combustor's wall and emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). The combustion experiments were conducted using three different oil burner nozzles (1.25, 1.50 and 1.75 USgal/h) under lean (equivalence ratio (φ) = …

Phase Change Materials-Assisted Heat Flux Reduction: Experiment And Numerical Analysis, Hussein J. Akeiber, Seyed Ehsan Hosseini, Mazlan A. Wahid, Hasanen M. Hussen, Abdulrahman Th Mohammad

Faculty Publications - Mechanical Engineering

Phase change materials (PCM) in the construction industry became attractive because of several interesting attributes, such as thermo-physical parameters, open air atmospheric condition usage, cost and the duty structure requirement. Thermal performance optimization of PCMs in terms of proficient storage of a large amount of heat or cold in a finite volume remains a challenging task. Implementation of PCMs in buildings to achieve thermal comfort for a specific climatic condition in Iraq is our main focus. From this standpoint, the present paper reports the experimental and numerical results on the lowering of heat flux inside a residential building using PCM, …

Inżynieria Chemiczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

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Oscillating Heat Pipe Performance With Evaporator Section Modifications, Mitchell Hoesing

Electronic Theses and Dissertations

The continuous development of electronic components to become faster and smaller has led to an increasing problem with thermal management. Thermal management ensures that the component operating temperatures are within a safe range, which maintains performance and improves reliability and lifespan. Traditional thermal management devices, such as the extruded-fin heat sink, are incapable of maintaining the safe operating temperature range for current and future high heat flux cooling applications. A device that has the capability to meet this growing need is the oscillating heat pipe. Oscillating heat pipes (OHPs) are passive, two-phase cooling devices that have been shown to transfer …

An Experimental Investigation Of Heat Transfer For Arrays Of Impingement Jets Onto The Featured Surfaces With Cylindrical And Elliptical Raised Surfaces, Marc A. Medina

Honors Undergraduate Theses

This study focuses on multi-jet impingement for gas turbine geometries in which the objective is to understand the influence of the roughness elements on a target surface to the heat transfer. Current work has proven that implementing roughness elements for multi-jet impingement target surfaces has increased heat transfer ranging anywhere from 10-30%. This study has chosen to investigate three different roughness elements, elliptical in cross-section, to compare to smooth surface geometries for multi-jet impingement. An experimental was taken for this study to extend the current knowledge of multi-jet impingement geometries and to further understand the heat transfer performance. A temperature …

An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic …

Experimental Investigation Of Fast Pyrolysis Of Arundo Donax In A Novel Paddle Reactor, Chintan Desai

Dissertations, Master's Theses and Master's Reports

The main objective of this research was to show the effectiveness of a novel paddle reactor for fast pyrolysis and study the effect of biomass particle size and reaction temperature of Arundo Donax a type of energy crop on the bio-oil yields. The novel paddle reactor showed effective mixing and heat transfer which were proved with the help of studying the residence time and the heating characteristics of the system respectively. The effect of different biomass particle sizes on the bio-oil yield was not significant, the bio-oil yield was approximately 50% for all the sizes. For Arundo Donax particle sizes …

Low Temperature Split Injection Spray Combustion: Ignition, Flame Stabilization And Soot Formation Characteristics In Diesel Engine Conditions, Ahmed Abdul Moiz

Dissertations, Master's Theses and Master's Reports

The aim of the PhD work is to investigate the fundamental differences in combustion behavior when split injections are used in low temperature combustion regime. In this thesis, the first injection is also called as pilot injection and second injection is also called as main injection. The broad aspects which are studied encompassing the investigation is to study the ignition delay, lift-off and soot formation of such a double split spray combustion. The mechanisms of ignition, lift-off and soot production are to be studied since the main ignition and lift-off were found to differ from the pilot which effect net …

An Experimental Investigation Of The Effect Of Temperature And Space Velocity On The Performance Of A Cu-Zeolite Flow-Through Scr And A Scr Catalyst On A Dpf With And Without Pm Loading, Vaibhav Kadam

Dissertations, Master's Theses and Master's Reports

Abstract The heavy-duty diesel (HDD) engines use the diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and urea injection based selective catalytic reduction (SCR) systems in sequential combination, to meet the US EPA 2010 PM and NOₓ emission standards. The SCR along with a NH₃ slip control catalyst (AMOX) offer NOₓ reduction >90 % with NH₃ slipHowever, there is a strong desire to further improve the NOₓ reduction performance of such systems, to meet the California Optional Low NOₓ Standard implemented since 2015. Integrating SCR functionality into a diesel particulate filter (DPF), by coating the SCR catalyst on the DPF, …

Shear Driven Suppressed Nucleation Annular Flow-Boiling In Millimeter-Scale Channels: Direct Numerical Simulations, Sharayu Bhasme

Dissertations, Master's Theses and Master's Reports

Many contemporary high heat-flux cooling applications are facilitated by mm-scale flow-boilers that operate in the steady annular suppressed nucleation regime (i.e., a thin evaporating liquid film flow covers the heated boiling-surface).

For such cases, this thesis presents a direct numerical simulation (DNS) approach. The steady algorithm and its accuracy are discussed. Representative detailed solutions for annular flow-boiling of FC-72 in a horizontal channel are presented.