Mechanical Engineering Commons^™

Design And Simulation Analysis Of A Bipv (Building Integrated With Pv) Air-Duct System For Residential High-Performance Development, Arash Zarmehr

Electronic Theses and Dissertations, 2020-

A growing number of buildings are integrating building-integrated photovoltaics (BIPV) devices to increase energy efficiency and reduce energy costs. A building's heating and cooling loads are impacted by the thermal resistance of the air duct BIPV because of the change in thermal resistance. Therefore, augmenting the efficiency of (BIPV) devices will benefit many building architectures and mechanical engineering applications. This work introduces a low-cost and low- maintenance air duct system design augmenting BIPV systems. This novel approach increases airflow velocity and decreases air temperature for BIPV, resulting in improved performance for the PV system electricity output, increased PV lifespan due …

Lithium-Ion Battery Prognosis With Variational Hybrid Physics-Informed Neural Networks, Renato Giorgiani Do Nascimento

Electronic Theses and Dissertations, 2020-

Lithium-ion batteries are an increasingly popular source of power for many electric applications. Applications range from electric cars, driven by thousands of people every day, to existing and future air vehicles, such as unmanned aircraft vehicles (UAVs) and urban air mobility (UAM) drones. Therefore, robust modeling approaches are essential to ensure high reliability levels by monitoring battery state-of-charge (SOC) and forecasting the remaining useful life (RUL). Building principled-based models is challenging due to the complex electrochemistry that governs battery operation, which would entail computationally expensive models not suited for prognosis and health management applications. Alternatively, reduced-order models can be used …

Synthesis And Assessment Of Sustainable Fuels For Transportation And Space Exploration, Katerina Chagoya

Electronic Theses and Dissertations, 2020-

As global energy sources transition towards renewable energy, the demand for sustainable fuels has never been greater. The sheer scale of this transition will require numerous solutions to accommodate for the diverse and complex situations worldwide. This dissertation will discuss 3 studies: the utilization of CO2 waste gas to produce fuels sustainably, characterizing biofuels for efficient use in automobiles, and developing a solid, emissonless fuel intended for spaceflight but also applicable on Earth. The hydrogenation of CO2 into value-added molecules could reduce greenhouse gas emissions if waste stream CO2 were captured for conversion. We found that atomic vacancies induced in …

Studies On Powder Compaction And Wire Extrusion Of Pure Metals And Metal/Cnt Nano Composites, Qiang Zhou

Electronic Theses and Dissertations, 2020-

The goal of this dissertation is to fabricate wires made of Cu/CNT and Al/CNT composites with good mechanical strength and super thermal/electrical conductivities using powder compaction and wire extrusion manufacturing processes. Powder compaction was studied using both test and simulation. Cold compaction, hot compaction and vibration assisted (cold) compaction tests were conducted to achieve different density ratios. Hot compaction tests improved about 6% compared with cold compaction under the same compression pressure. Although the relative density ratio does not obviously improve at vibration assisted (cold) compaction, the strength of the specimens made under vibration loading is much better than those …

Econometric Frameworks For Energy Prediction, Naveen Chandra Iraganaboina

Electronic Theses and Dissertations, 2020-

Global warming and associated role of energy consumption across various sectors is a well-researched topic in recent years. Understanding current urban energy consumption patterns will allow us to understand how future energy consumption patterns will evolve. With electrification of vehicles and potentially altering culture of work from home, the energy usage at regional level would see a significant change in the future. The current PhD dissertation contributes to energy consumption analysis of a region by analyzing residential energy consumption, commercial energy consumption and transportation energy use by households. The aggregation of these energy consumption within a region contributes to the …

Harvesting Heat From Safer, Energy-Dense Slow Pyrolant Mixtures For Future Space Missions, Katerina Chagoya

Electronic Theses and Dissertations, 2020-

Energy sources powering space missions range from highly energetic nuclear reactions to short-lifetime and low-output batteries. The proper selection of a power system is dependent on the mission duration and destination and oftentimes energy sources that may be optimal for the former may be unsuitable for the latter. Various limitations of these power sources hinder the capacity for regular and frequent space exploration. However, the ability to harvest heat for electrical power generation would allow for long-distance and long-duration missions at a reduced cost. By employing a regulated, self-propagating, exothermic chemical reaction between solid fuel and oxidizer, we hope to …

Engineering The Surface Chemistry And Surface Conditions To Optimize The Heat Removal Rate Of Various Surfaces, Thomas Germain

Electronic Theses and Dissertations, 2020-

As the demand for more powerful and smaller electronics rise, the need for creative cooling solutions to prevent burnout becomes increasingly paramount. In response to recent cooling needs, new cooling techniques, such as jet impingement cooling, spray cooling, and heat pipes, have risen in popularity for their simple design and efficiency in thermal transport. This interest has risen in both industry and academia, where research has been conducted to optimize the heat transfer performance for these systems and how these systems can be implemented in new technologies. One method that has risen in interest is affecting the surface, through physical …

Design Of An Annular Disc-Shaped Heat Pipe For Air-Cooled Steam Condensers, Ahmad Saleh

Electronic Theses and Dissertations, 2020-

Limitations on water utilization are turning into an expanding issue for the power and electricity generation industry. As a contribution to the solution of water consumption problems, utility companies are shifting toward using air-cooled condensers (ACC) in replace to the typical water-cooling methods of once-through cooling and the surface condenser/wet-cooling tower combination. Although the ACC is a dry cooling method, the industry is quite hesitant to switch over to ACC mainly for three reasons: (a) lower power output, (b) higher capital cost, and (c) larger physical footprint. All these drawbacks are because of the high overall thermal resistance of condensing …

Dynamic Behavior And Performance Of Different Types Of Multi-Effect Desalination Plants, Mohamed Abdelkareem

Electronic Theses and Dissertations

Water and energy are two of the most vital resources for the socio-economic development and sustenance of humanity on earth. Desalination of seawater has been practiced for some decades and is a well-established means of water supply. However, this process consumes large amounts of energy and the global energy supply is also faced with some challenges. In this research, multi-effect desalination (MED) has been selected due to lower cost, lower operating temperature and efficient in terms of primary energy and electricity consumption compared to other thermal desalination systems. The motivation for this research is to address thermo-economics and dynamic behavior …

Optimal Sintering Temperature Of Ceria-Doped Scandia Stabilized Zirconia For Use In Solid Oxide Fuel Cells, Amanda K. Assuncao

Honors Undergraduate Theses

Carbon emissions are known to cause decay of the Ozone layer in addition to creating pollutant, poisonous air. This has become a growing concern among scientists and engineers across the globe; if this issue is not addressed, it is likely that the Earth will suffer catastrophic consequences. One of the main culprits of these harmful carbon emissions is fuel combustion. Between vehicles, power plants, airplanes, and ships, the world consumes an extraordinary amount of oil and fuel which all contributes to the emissions problem. Therefore, it is crucial to develop alternative energy sources that minimize the impact on the environment. …

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 …

A Performance Comparison Of Solar Radiation Predictive Models For Both Fixed And Tracking Surfaces, William F. Marion

Retrospective Theses and Dissertations

Accurate performance prediction for a system utilizing solar energy requires accurate estimates of the solar radiation received by the collector surface. This thesis compares the performance of five different diffuse solar radiation models in estimating the diffuse radiation received by a tilted surface in the warm, humid climate of Central Florida.

The following models were studied: Isotropic Model, Temps and Coulson Model, Klucher Model, Hay Model, and Perez Model. The models were evaluated for both a fixed south facing surface and for three different tracking schemes suitable for photovoltaic applications. Model estimates were then compared to the solar radiation data …

A Cavity Absorber For A Focusing Solar Collector, Andrew W. Crapo

Retrospective Theses and Dissertations

The concept of a cavity absorber for use with a focusing parabolic trough is developed in this paper. A mathematical model is formulated and used to compare different absorber geometries. Limitations of the model are discussed and within the range of materials and fabrication methods available, the choice of a cylindrical cavity is substantiated. Relative sizes of the gap and cylinder are chosen for a given mirror arc length, focal length, and alignment error. The model is used to optimize these parameters and predict absorber and collector efficiency. The processes of building and testing the absorber are detailed, and test …