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Theses/Dissertations

2015

Mechanical Engineering

University of Louisville

Articles 1 - 8 of 8

Full-Text Articles in Engineering

Application Of The Aeroacoustic Analogy To A Shrouded, Subsonic, Radial Fan., Bryan Buccieri Dec 2015

Application Of The Aeroacoustic Analogy To A Shrouded, Subsonic, Radial Fan., Bryan Buccieri

Electronic Theses and Dissertations

A study was conducted to investigate the predictive capability of computational aeroacoustics with respect to a shrouded, subsonic, radial fan. A three dimensional unsteady fluid dynamics simulation was conducted to produce aerodynamic data used as the acoustic source for an aeroacoustics simulation. Two acoustic models were developed: one modeling the forces on the rotating fan blades as a set of rotating dipoles located at the center of mass of each fan blade and one modeling the forces on the stationary fan shroud as a field of distributed stationary dipoles. Predicted acoustic response was compared to experimental data. The blade source …

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Evaluation Of Two-Phase Evaporation Pressure Drop Correlations For Low Refrigerant Mass Flux., Anna Fenko Dec 2015

Evaluation Of Two-Phase Evaporation Pressure Drop Correlations For Low Refrigerant Mass Flux., Anna Fenko

Electronic Theses and Dissertations

This study was conducted to evaluate three currently popular two-phase pressure drop models for extremely low velocity refrigerant flow through smooth circular evaporators in household refrigeration systems. Experimental data was taken at mass fluxes under 70 kg/m2s for two refrigerants, R134A and R600A, internal diameters of aluminum evaporators ranging from 0.186 to 0.317 inches, U-bend internal radii ranging from 0.342 to 0.750 inches in horizontal and vertical orientations of evaporators. The geometry of the samples closely resembled a commonly used serpentine shape with multiple U-bends experiencing both, up- and down-flow of the refrigerant. Two empirical models, Müller-Steinhagen & …

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Performance Analysis Of A Copper Ii Sulfate Pentahydrate Based Thermogalvanic Cell., Steffen Krebs Aug 2015

Performance Analysis Of A Copper Ii Sulfate Pentahydrate Based Thermogalvanic Cell., Steffen Krebs

Electronic Theses and Dissertations

Low grade heat recovery systems are more relevant today due to the rising costs in energy and transition to non-fossil fuel energy sources. Thermogalvanic cells show potential due to low cost and scalability. In this study the performance of a Copper II Sulfate Pentahydrate based electrolyte was evaluated. The effects of electrolyte concentration, electrode separation, and electrode surface area were studied experimentally. Conductive heat transfer within the electrolyte was simulated via SolidWorks. All experimental thermocell testing was conducted to find the maximum power production of a particular cell design. The base cell had a six inch electrode separation with two …

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Mechanics Of Electrode Materials In Lithium Battery Applications., Jubin Chen Aug 2015

Mechanics Of Electrode Materials In Lithium Battery Applications., Jubin Chen

Electronic Theses and Dissertations

During lithiation and detlithiation, substantial volumetric changes occur within the electrode materials used for rechargeable lithium batteries. The magnitude of these deformations is inherently linked to the electrical capacity of the battery electrical capacity, which tends to degrade with repeated cycling. In this dissertation, the relationship between electrical discharge capacity and mechanical deformation state is examined using in-situ imaging of the working electrode surface within a custom CR2032 coin cell lithium battery. Digital image correlation is used to quantify electrode strains throughout the discharge-charge process. The effect of constraint due to substrate stiffness is investigated for two film materials: traditional …

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Vanadium Trichloride Thermochemical Solar Energy Storage System Analysis., Caleb Michael Rogers May 2015

Vanadium Trichloride Thermochemical Solar Energy Storage System Analysis., Caleb Michael Rogers

Electronic Theses and Dissertations

As annual energy consumption grows, developing renewable solar energy conversion systems, storage systems, and high density electrical energy production systems is growing increasingly important. The proposed system utilizes vanadium trichloride thermal decomposition to produce chlorine gas and vanadium dichloride. A second reaction combines gaseous hydrogen chloride and the product vanadium dichloride to reform vanadium trichloride and produce hydrogen gas. Hydrogen gas and chlorine gas can be stored indefinitely and electrical energy is obtained from the chemicals by a non-humidified dry membrane hydrogen – chlorine fuel cell. The fuel cell produces the gaseous hydrogen chloride needed to reform vanadium trichloride. The …

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Bi-Stable Buckled Energy Harvesters Actuated Via Torque Arms., Daniel Allen Porter May 2015

Bi-Stable Buckled Energy Harvesters Actuated Via Torque Arms., Daniel Allen Porter

Electronic Theses and Dissertations

Vibrational energy harvesters (VEH) are one way to generate electricity. Though the energy quantities are not enough to run desktop computers, they can power remote devices such as temperature, pressure, and accelerometer sensors or power biological implants. New versions of the Bluetooth protocol can even be used with VEH technology to send wireless data. An important aspect of VEH devices is the power output, operating frequency, and bandwidth. This dissertation investigates a novel method of actuating the primary buckled energy harvesting structure using torque arms as a force amplification mechanism. Buckled structures can exhibit snap-through and has the potential to …

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Development Of A Surrogate Bruising Detection System To Describe Potential Bruising Patterns Associated With Common Childhood Falls., Raymond Dsouza May 2015

Development Of A Surrogate Bruising Detection System To Describe Potential Bruising Patterns Associated With Common Childhood Falls., Raymond Dsouza

Electronic Theses and Dissertations

Child abuse is a leading cause of fatality in children aged 0-4 years. An estimated 1,700 children die annually as a result of child abuse of which threequarters (75.7%) of the children were younger than 4 years old1. Infants (younger than 1 year) had the highest rate of fatalities among the group. Many of the serious injuries and fatalities could have potentially been prevented if clinicians and child protective services were able to better distinguish between injuries associated with abuse versus those caused by accidents. Missed cases of child abuse have been shown to be as high as 71% of …

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Experimental And Analytical Study Of An Open Cathode Polymer Electrolyte Membrane Fuel Cell., Alex Martin Bates May 2015

Experimental And Analytical Study Of An Open Cathode Polymer Electrolyte Membrane Fuel Cell., Alex Martin Bates

Electronic Theses and Dissertations

In this thesis four different fuel cell designs were simulated with consideration for electrochemical effects, reactant species transport, and heat transfer. Simulation results include the mass fraction of hydrogen, oxygen, and water, temperature gradient, pressure gradient, and velocity profile. One of the fuel cell designs was experimentally tested using two different membrane electrolyte assemblies; one high performance and the other high durability. The polarization curve resulting from simulation compares well with the polarization curve produced by experimental work. A 16 cell fuel cell stack was simulated with consideration for stack compression. The same fuel cell stack was tested experimentally for …

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