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The Effect Of Mesh-Type Bubble Breakers On Two-Phase Vertical Co-Flow, Alan Kalbfleisch 2016 The University of Western Ontario

The Effect Of Mesh-Type Bubble Breakers On Two-Phase Vertical Co-Flow, Alan Kalbfleisch

Electronic Thesis and Dissertation Repository

It is proposed that mesh-type bubble breakers can be used in two-phase gas-liquid vertical cocurrent pipe flow to enhance the heat and mass transfer rates. Two experimental studies were performed to investigate the effect of mesh-type bubble breakers with varying geometries on two-phase flow behaviour. The first used highspeed imaging to measure bubble size and observe the resulting flow regime for two-phase vertical co-flow consisting of air and water. A Froude number correlation that can be used to predict the bubble size generated by mesh-type bubble breakers is proposed. Flow regime maps for two-phase flow in the presence of bubble ...


Me 350 Air Conditioning Experiment, Joshua Baida, Ellie Hallner, Tyler Eschenbach 2016 California Polytechnic State University, San Luis Obispo

Me 350 Air Conditioning Experiment, Joshua Baida, Ellie Hallner, Tyler Eschenbach

Mechanical Engineering

In keeping with Cal Poly's focus on physically applying the concepts learned in the classroom, our team of engineering students has compiled a laboratory experiment displaying the basic thermodynamic cycle found in air conditioning systems. This vapor compression cycle is displayed on a visualization board that features all four major components of the system: the compressor, the evaporator, the condenser, and the throttling valve. Students will take measurements of temperature and pressure at each stage in the cycle and also gauge the power draw from the compressor to gain an understanding of how performance and electricity cost come into ...


Efficiency Testing Of An Electronic Speed Controller, Grace Cowell, Matthew Hudson, Marcus Pereira 2016 California Polytechnic State University, San Luis Obispo

Efficiency Testing Of An Electronic Speed Controller, Grace Cowell, Matthew Hudson, Marcus Pereira

Mechanical Engineering

This project required the development of a rig that could experimentally determine the efficiency of an Electronic Speed Controller (ESC). The selected design focuses on measuring the losses due to heat from the device and comparing this to its input power. The selected design is a flow rig that utilizes the heat equation q=ṁcpΔT. The rig provides a steady state measurement of the ESC heat output by passing a known mass flow rate of air across the ESC and measuring the temperature difference. It uses a flowmeter to determine ṁ, thermocouples to determine ΔT, and a table lookup to ...


Fluid Analysis In Solar Heat Pipes, Ben Krumholz, Michael Agavo, William Dundon 2016 California Polytechnic State University, San Luis Obispo

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 ...


Continuum Modeling Of The Densification Of W-Ni-Fe During Selective Laser Sintering, Connor M. West 2016 California Polytechnic State University, San Luis Obispo

Continuum Modeling Of The Densification Of W-Ni-Fe During Selective Laser Sintering, Connor M. West

Master's Theses and Project Reports

The purpose of this thesis is to effectively model the time history of the temperature distribution during the selective laser sintering process and use this information to investigate the resulting relative density. The temperature is a critical parameter of the process because it directly effects the overall quality of the part. First, an efficient, affordable, and reliable simulation was developed within the finite element software, Abaqus. Next, the results from the simulations were compared to the experimental results performed by Wang et al. (2016). The FEA model consisted of a 3 layer simulation. Multiple simulations at various laser recipes were ...


A Numerical Study Of Compressible Lid Driven Cavity Flow With A Moving Boundary, Amer Hussain 2016 UNIVERSITY OF NEW ORLEANS

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 ...


Effect Of Non-Uniform Air-Side Velocity Distribution On Heat Transfer Model Predictions For Microchannel Condenser., Zachary Chapin 2016 University of Louisville

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 ...


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 2016 University of Tennessee, Knoxville

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

University of Tennessee Honors Thesis Projects

No abstract provided.


Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby 2016 University of Tennessee - Knoxville

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 ...


Leidenfrost Energy Barriers, James Peck, Anton Hassebrook, Craig Zuhlke, Troy Anderson, Dennis Alexander, George Gogos, Sidy Ndao 2016 University of Nebraska - Lincoln

Leidenfrost Energy Barriers, James Peck, Anton Hassebrook, Craig Zuhlke, Troy Anderson, Dennis 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 ...


Numerical Investigation Of Full Scale Thunderstorm Downbursts: A Parametric Study And Comparison To Meteorological Model, Christopher Oreskovic 2016 The University of Western Ontario

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 ...


A Model For Complex Heat And Mass Transport Involving Porous Media With Related Applications, Furqan A. Khan 2016 The University of Western Ontario

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 ...


Modeling Of Methane Tank Depressurization In Cold Weather, Brittney Bridger-Burton, Kevin Cole 2016 University of Nebraska - Lincoln

Modeling Of Methane Tank Depressurization In Cold Weather, Brittney Bridger-Burton, Kevin 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 2016 Marquette University

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 ...


Application Of Natural Convection For Photovoltaic Cooling And Photocatalytic Disinfection, Usman J. Rajput 2016 The University of Western Ontario

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 ...


Procesy Cieplne I Aparaty (Lab), Wojciech Budzianowski 2016 Wroclaw University of Technology

Procesy Cieplne I Aparaty (Lab), Wojciech Budzianowski

Wojciech Budzianowski

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Economical Retrofit System To Reduce Cooking Emissions In Third World Dwellings, Jonathan VanZummeren, Tyler Sturgeon, Ben Dalessandro 2016 University of Akron

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

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 ...


An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur 2016 Michigan Technological University

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 ...


Energy Resources Use Metrics, Rahul Y. Nehete 2016 University of Kentucky

Energy Resources Use Metrics, Rahul Y. Nehete

Theses and Dissertations--Mechanical Engineering

Energy resources use has been considered as a key component of sustainable development. Data related to global, regional, state, sector, industry and process demonstrate that a significant reduction of energy resources for a given production rate in manufacturing processes requires an introduction of transformational technologies at the process level, propagating the impact to higher scales, leading not just to a gradual improvement of traditional technologies but to more sustainable development.

The study offers two approaches to the formulation of the limits of energy use in the context of sustainable development. The first is to construct a map of key selected ...


Flow Visualization Of Buoyant Instability In A Cross-Flow: An Implication For Flame Spread Over Forest Fuel Beds, Nikolay Gustenyov 2016 University of Kentucky

Flow Visualization Of Buoyant Instability In A Cross-Flow: An Implication For Flame Spread Over Forest Fuel Beds, Nikolay Gustenyov

Theses and Dissertations--Mechanical Engineering

This thesis reports small-scale laboratory experiments designed to visualize the flow over a heated plate. A low-speed wind tunnel was built, and a heating plate was flush mounted on the wind tunnel floor to provide a uniform heat flux over its surface. A paper thin cloth soaked with commercially available Vaseline was placed on top of the heating plate to produce thick smoke streaks that were carried downstream by a horizontal airflow. Both LED light and a laser sheet of approximately 30-degrees open angle were separately used to illuminate this flow, the latter advanced downstream with 1-cm interval from the ...


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