Energy Systems Commons^™

Modeling Mass And Thermal Transport In Thin Porous Media Of Pem Fuel Cells, Vinaykumar Konduru

Dissertations, Master's Theses and Master's Reports

Water transport in the Porous Transport Layer (PTL) plays an important role in the efficient operation of polymer electrolyte membrane fuel cells (PEMFC). Excessive water content as well as dry operating conditions are unfavorable for efficient and reliable operation of the fuel cell. The effect of thermal conductivity and porosity on water management are investigated by simulating two-phase ow in the PTL of the fuel cell using a network model. In the model, the PTL consists of a pore-phase and a solid-phase. Different models of the PTLs are generated using independent Weibull distributions for the pore-phase and the solid-phase. The …

The Impact Of Water Injection On Spark Ignition Engine Performance Under High Load Operation, Jeremy Worm

Dissertations, Master's Theses and Master's Reports

An experimental effort has been completed in which water injection was investigated as a means of enabling increases in engine output and high load efficiency. Water was injected into the intake port of a direct fuel injected, 4-cylinder, boosted engine with dual independent variable valve timing. The water was shown to increase volumetric efficiency and decrease the onset of knock which in turn enable more optimal combustion phasing. Both of these affects resulted increases in load of up to 5.5% at the same manifold pressure as the baseline case. The advancement of combustion phasing, combined with elimination of fuel enrichment …

Test 2183: Claas Axion 880, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nfpa Fluid Power Vehicle Challenge, Ean H. Dickerhoof

Williams Honors College, Honors Research Projects

Every year the National Fluid Power Association hosts a Fluid Powered Vehicle Challenge, this exposes students from universities all around the United States to the power and possibilities of hydraulics. This year the University of Akron’s team of engineers set out to design a bicycle that would be competitive and innovative in all aspects of the competition. In order to accomplish this, the designed bicycle must excel in three categories of competition; a sprint race, an endurance race, and an efficiency challenge.

To accomplish this task the University of Akron’s team of engineers used a lightweight bicycle frame with many …

Heat Transfer Analysis In A Paddle Reactor For Biomass Fast Pyrolyis, Ankith Ullal

Dissertations, Master's Theses and Master's Reports

Heat transfer analysis was performed on a novel auger reactor for biomass fast pyrolysis. As part of this analysis, correlations for specific heat capacity and heat transfer coefficients for biomass (sawdust) and sand (used as heat transfer medium) were developed. For sand, the heat transfer coefficient followed a power law distribution with reactor fill level and temperature. For raw biomass, the heat transfer coefficient also showed similar dependence on fill level, but was independent of temperature up to 300°C. These correlations were used in a one dimensional heat transfer model developed to calculate the heating time and heating rate of …

Solar Irradiance Forecasting And Implications For Domestic Electric Water Heating, Christopher Nutter

College of Graduate Studies: Theses & Dissertations

As the effects of burning fossil fuels continues to present its prevalence, the interests in alternative forms of energy is expanding. Within the home, the domestic electrical water heater accounts for approximately 17% of its energy consumption. Reducing the amount of energy required to produce hot water from this thermal system alone can have a significant effect on reducing its carbon footprint. In this presented work, a modeled domestic electrical water heater was supplied photovoltaic and on-grid electrical power to increase its energy efficiency. As photovoltaic (PV) energy is directly related to solar irradiation, it is important to receive accurate …

Hybrid Metal Oxide Cycle Water Splitting, Richard B. Diver Jr., Robert D. Palumbo, Nathan P. Siegel, James E. Miller

Other Faculty Research and Publications

Hybrid thermochemical water splitting systems are disclosed that thermally reduces metal oxides particles to displace some but not all of the electrical requirements in a water splitting electrolytic cell. In these hybrid systems, the thermal reduction temperature is significantly reduced compared to two-step metal-oxide thermochemical cycles in which only thermal energy is required to produce hydrogen from water. Also, unlike conventional higher temperature systems where the reduction step must be carried out under reduced oxygen pressure, the reduction step in the proposed hybrid systems can be carried out in air, allowing for thermal input by a solar power tower with …

Design Of Electrical Layout Of Offshore Wind Farms, Shirshak K. Dhali, Mahidhar Nandigam

Electrical & Computer Engineering Faculty Publications

The cost and efficiency of offshore wind farms are determined by a variety of factors which include the type of electrical system (AC or DC), transmission length, transmission voltage, rated power, wind turbine type, farm topology, and wind speed. Since the design variable space is large for such problems, computational optimization is necessary to find an optimal solution. This paper discusses a design methodology to determine the optimal values of components to minimize the cost of an offshore wind farm. The cost, loss, reliability models, and the application of geometric programing for optimization of the layout and configuration of an …

Exploiting Modern Image Processing In Surface Flow Visualisation, Tarek Ihab Abdelsalam, Richard Williams, Grant Ingram

Mechanical Engineering

Surface flow visualisation is an experimental technique where the surface of interest is painted with an oil and dye mixture before a flow is applied to the object. In regions of high shear stress the oil/dye mixture is then removed and in regions of low shear stress the oil/dye mixture stays or builds up. The resulting pattern can be analysed to determine the structure near the surface under test, this is normally done in a qualitative manner with flow structures being identified based on the expertise of the experimentalist. Modern image processing tools can identify shapes and lines in pictures …

Processing, Microstructure, And Mechanical Properties Of Zirconium Diboride-Molybdenum Disilicide Ceramics And Dual Composite Architectures, Ryan Joseph Grohsmeyer

Doctoral Dissertations

"This research had two objectives: characterization of processing-microstructure-mechanical property relationships of conventional ZrB₂-MoSi₂ ceramics at room temperature (RT) and 1500⁰C in air, and fabrication of ZrB₂-MoSi₂ dual composite architectures (DCAs) for use near 1500⁰C. Elastic moduli, fracture toughness, and flexure strength were measured at RT and 1500⁰C for 15 ZrB₂-MoSi₂ ceramics hot pressed using fine, medium, or coarse ZrB₂ starting powder with 5-70 vol.% MoSi₂, referred to as FX, MX, and CX respectively where X is the nominal MoSi₂ content. MoSi₂ decomposed during sintering, resulting in …

Performance Analysis On Free-Piston Linear Expander, Furkan Kodakoglu

UNF Graduate Theses and Dissertations

The growing global demand for energy and environmental implications have created a need to further develop the current energy generation technologies (solar, wind, geothermal, etc.). Recovering energy from low grade energy sources such as waste heat is one of the methods for improving the performance of thermodynamic cycles. The objective of this work was to achieve long-term steady state operation of a Free-Piston Linear Expander (FPLE) and to compare the FPLE with the currently existing expander types for use in low temperature energy recovery systems. A previously designed FPLE with a single piston, two chambers, and linear alternator was studied …

The Role Of Active Flow-Control Devices In The Dynamic Aeroelastic Response Of Wind Turbine Rotors, Muraleekrishnan Menon Menon Muraleedharan Nair

Dissertations, Master's Theses and Master's Reports

The significance of wind as a renewable source of power is growing with the increasing capacity of individual utility-scale wind turbines. Contemporary wind turbines are capable of producing up to 8 MW and consequently, their rotor sizes are rapidly growing in size. This has led to an increased emphasis on studies related to improvements and innovations in load-control methodologies. Most often than not, controlling the loads on an operational turbine is a precarious scenario, especially under high wind loading. The up-scaling of turbine rotors would thus benefit from a rationale change in load control through methodologies such as variable-speed stall, …

Impact Of Natural Gas Direct Injection On Thermal Efficinecy In A Spark Ignition Engine, James Sevik

Dissertations, Master's Theses and Master's Reports

Interest in natural gas as an internal combustion engine fuel has been renewed due to its increasing domestic availability and stable price relative to other petroleum fuel sources. Natural gas, comprised mainly of methane, allows for up to a 25% reduction in engine out CO2 emissions due to a more favorable hydrogen-to-carbon ratio, relative to traditional petroleum sources. Traditional methods of injecting natural gas can lead to poor part-load performance, as well as a power density loss at full load due to air displacement in the intake manifold. Natural gas direct injection, which allows the fuel to be injected directly …

Model-Based Control Of Hybrid Electric Powertrains Integrated With Low Temperature Combustion Engines, Ali Soloukmofrad

Dissertations, Master's Theses and Master's Reports

Powertrain electrification including hybridizing advanced combustion engines is a viable cost-effective solution to improve fuel economy of vehicles. This will provide opportunity for narrow-range high-efficiency combustion regimes to be able to operate and consequently improve vehicle’s fuel conversion efficiency, compared to conventional hybrid electric vehicles (HEV)s. Low temperature combustion (LTC) engines offer the highest peak brake thermal efficiency reported in literature, but these engines have narrow operating range. In addition, LTC engines have ultra-low soot and nitrogen oxides (NOx) emissions, compared to conventional compression ignition and spark ignition (SI) engines. This dissertation concentrates on integrating the LTC engines (i) in …

Development Of A High-Fidelity Model And Kalman Filter Based State Estimator For Simulation And Control Of Nox Reduction Performance Of A Scr Catalyst On A Dpf, Venkata Rajesh Chundru

Dissertations, Master's Theses and Master's Reports

Reduction of emissions and improving the fuel consumption are two prime research areas in Diesel engine development. The present after-treatment systems being used for emissions control include diesel oxidation catalyst (DOC) for NO, HC and CO oxidation along with catalyzed particulate filters for PM (particulate matter) and selective catalytic reduction (SCR) for controlling NOx emissions. Recently an after-treatment system called SCR catalyst on a DPF capable of simultaneously reducing both NOx and PM emissions has been developed in order to reduce the overall size of the after-treatment system.

The goal of this proposed research is to create a state estimator …

Florida Rural Small Business Energy Assistance Collaborative Cumulative Report Ending December 31, 2016, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

The U.S. Department of Agriculture's (USDA) Rural Development initiative reaches out to communities across America with many programs (http://www.rd.usda.gov/programs-services/all-programs). USDA's Rural Energy for America Program (REAP) offers grants and loan guarantees for energy efficiency improvements and renewable energy systems to agriculture operations and qualifying rural small businesses. USDA has awarded the University of Central Florida a grant to provide a limited number of subsidized Energy Audits to eligible businesses in Florida in support of USDA Rural Development (USDA-RD) Grant and Loan programs for rural small businesses. The ultimate goal of the energy audits is to increase participation in REAP. Audits …

Phased Retrofits In Existing Homes In Florida Phase Ii: Shallow Plus Retrofits [Revised], Florida Solar Energy Center, Karen Sutherland

FSEC Energy Research Center®

The U.S. Department of Energy Building America team Partnership for Improved Residential Construction is collaborating with Florida Power & Light Company (FPL) to conduct a phased residential energy-efficiency retrofit program. This research seeks to determine the impacts on annual energy reductions from the installation of advanced residential technologies. Earlier project work involving the application of two levels of retrofit, shallow and deep, found average savings of 9% and 38%, respectively. Whole-house demand reduction among the deep retrofit homes averaged 39% during FPL's peak summer hour. These savings levels approach the Building America program goals of reducing whole-house energy use of …

Energy-Efficient Management Of Mechanical Ventilation And Relative Humidity In Hot-Humid Climates, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

The U.S. Department of Energy's Building America research team Building America Partnership for Improved Residential Construction conducted this research project to gain data and insight into these issues. The project focused on energy-efficient management of mechanical ventilation and RH during the cooling season. It consisted of eight test configurations. A particular focus evaluated how well a ductless seasonal energy-efficiency ratio (SEER) 21.5 mini-split heat pump (MSHP) could perform as the primary cooling system without a dehumidifier for supplemental dehumidification in a continuously mechanically ventilated house.

Photovoltaic Cooking In The Developing World, Tyler Watkins, Christopher O'Day, Omar Arriaga

Mechanical Engineering

The challenge of clean cooking is faced by hundreds of millions of people worldwide. We present a cooking technology consisting of a solar panel directly connected to an electric heater in a well-insulated chamber. Assuming continued decrease in solar panel prices, we anticipate that in a few decades Solar Electric Cooking technologies will be the most common cooking technology for the poor. Appropriate use of insulation reduces the power demand making low-power Insulated Solar Electric Cooking systems already cost competitive.

Thermal Transport In Lithium Ion Batteries: An Experimental Investigation Of Interfaces And Granular Materials, Aalok Jaisheela Uday Gaitonde

Open Access Theses

Increasing usage and recent accidents due to lithium-ion (Li-ion) batteries exploding or catching on fire has inspired research on the characterization and thermal management of these batteries. In cylindrical 18650 cells, heat generated during the battery's charge/discharge cycle is poorly dissipated to the surrounding through its metallic case due to the poor thermal conductivity of the jelly roll, which is spirally wound with many interfaces between electrodes and the polymeric separator. This work presents a technique to measure the thermal conduction across the metallic case-plastic separator interface, which ultimately limits heat transfer out of the jelly roll.

The polymeric separator …