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2016

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Full-Text Articles in Mechanical Engineering

College Of Engineering Senior Design Competition Fall 2016, University Of Nevada, Las Vegas Dec 2016

College Of Engineering Senior Design Competition Fall 2016, University Of Nevada, Las Vegas

Senior Projects (COE)

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the ...


Stationary Nonimaging Concentrators – A Comprehensive Study And Design Improvements, Srikanth Madala Dec 2016

Stationary Nonimaging Concentrators – A Comprehensive Study And Design Improvements, Srikanth Madala

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most places on our planet receive an annual average radiation between 800-1000 W/m2. In the man-made world, this radiation is largely incident on stationary structures such as buildings, roads, monuments, bridges etc. Moreover, in the natural world also, there are large tracts of barren land which can be put to good use given their solar energy potential. The vision of the current research is to concentrate all this available solar energy to a more readily usable form. Therefore, stationary nonimaging solar concentrator technologies are sought after. This dissertation work is an exhaustive research on the nonimaging concentrating mechanisms with ...


Modeling Pyrolysis Of Large Coal Particles With Many Species, Jianqing Li Oct 2016

Modeling Pyrolysis Of Large Coal Particles With Many Species, Jianqing Li

Master's Theses (2009 -)

Coal currently supplies 40% of the world’s electricity needs, and is one of the most important energy sources. As the initial stage of coal combustion, pyrolysis is a thermal decomposition process which converts coal into light gases and tars, which are subsequently consumed in combustion reactions, as well as solid char. Recently there has been interest in using slow pyrolysis as a stand-alone process for the production of chemicals and fuels from large (mm-scale) coal particles. Simulations can be used to efficiently study the impact of pyrolysis conditions on gas, tar and char yields, as well as gas and ...


Lattice Boltzmann Methods For Wind Energy Analysis, Stephen Lloyd Wood Aug 2016

Lattice Boltzmann Methods For Wind Energy Analysis, Stephen Lloyd Wood

Doctoral Dissertations

An estimate of the United States wind potential conducted in 2011 found that the energy available at an altitude of 80 meters is approximately triple the wind energy available 50 meters above ground. In 2012, 43% of all new electricity generation installed in the U.S. (13.1 GW) came from wind power. The majority of this power, 79%, comes from large utility scale turbines that are being manufactured at unprecedented sizes. Existing wind plants operate with a capacity factor of only approximately 30%. Measurements have shown that the turbulent wake of a turbine persists for many rotor diameters, inducing ...


How Can Occupancy Modeling And Occupancy Sensors Reduce Energy Usage In Academic Buildings: An Application Approach To University Of San Francisco, Paloma R. Duong May 2016

How Can Occupancy Modeling And Occupancy Sensors Reduce Energy Usage In Academic Buildings: An Application Approach To University Of San Francisco, Paloma R. Duong

Master's Projects and Capstones

Buildings are amongst the highest energy consumers relative to industry and transportation. They account for 40% of the world’s energy consumption, due to the need for lighting, equipment, heating, cooling and ventilation. Academic buildings are multi-purpose buildings that create a challenge on energy reduction. Most are old and have fixed occupancy schedules, resulting in high energy consumption because these buildings experience significant occupancy variation throughout the day. Five academic buildings were analyzed; their building information, energy consumption data and methods to project energy savings have been analyzed. The case studies presented different strategies on predicting energy savings, but these ...


College Of Engineering Senior Design Competition Spring 2016, University Of Nevada, Las Vegas May 2016

College Of Engineering Senior Design Competition Spring 2016, University Of Nevada, Las Vegas

Senior Projects (COE)

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the ...


Haul Truck Tires Recycling, Jessica N. Lizarazu May 2016

Haul Truck Tires Recycling, Jessica N. Lizarazu

Chemical Engineering Undergraduate Honors Theses

The disposal of large Off-the-Road (OTR) tires is an increasingly important concern. These tires can weigh up to 8,450 pounds with an overall diameter and width of approximately 140.7 inches and 45.1 inches respectively. OTR tires are used for mining vehicles such as haul trucks, wheel loaders, backhoes, graders, and trenchers. These new tires cost between $38,000 and $50,000 each, depending on multiple factors including oil prices and the cyclical nature of the industry. Haul trucks contain six tires per vehicle, and mines replace these tires around every 9-12 months. Statistics regarding discarded OTR tires ...


Parametric Analysis Of A Solid Oxide Fuel Cell Auxiliary Power Unit Operating On Syngas Produced By Autothermal Reforming Of Hydrocarbon Fuels, Jun Dong, Xinhai Xu, Ben Xu, Shuyang Zhang Apr 2016

Parametric Analysis Of A Solid Oxide Fuel Cell Auxiliary Power Unit Operating On Syngas Produced By Autothermal Reforming Of Hydrocarbon Fuels, Jun Dong, Xinhai Xu, Ben Xu, Shuyang Zhang

Mechanical Engineering Faculty Publications and Presentations

A 1 kWe integrated auxiliary power unit (APU) system consisting of an autothermal reformer and a solid oxide fuel cell (SOFC) unit, as well as balance-of-plant components, was designed and analyzed. A relatively easy-to-approach SOFC model was developed in order to conveniently calculate V-I and P-I curves and the system's net efficiency at different operating conditions. The effects of steam to carbon and oxygen to carbon ratios in the reactants, channel dimensions of the SOFC unit, and hydrocarbon fuel types on the integrated APU system's performance were discussed. Five hydrocarbon fuels including diesel, Jet-A, gasoline, ethanol, and methanol ...


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 Mar 2016

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 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.


Procesy Cieplne I Aparaty (Lab), Wojciech M. Budzianowski Jan 2016

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

Wojciech Budzianowski

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Inżynieria Chemiczna Lab., Wojciech M. Budzianowski Jan 2016

Inżynieria Chemiczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

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Understanding Biofuel Production Systems From An Economic And Environmental Perspective, Longwen Ou Jan 2016

Understanding Biofuel Production Systems From An Economic And Environmental Perspective, Longwen Ou

Graduate Theses and Dissertations

Biofuels are considered to be a promising sustainable alternative to traditional fossil fuels. There are many different technologies under development hence it is important to evaluate their economic potential and environmental impacts at early stage. This dissertation displays a systematic platform for evaluating performance of biofuel production systems by considering both economic and environmental metrics. It also demonstrates the necessity of incorporating uncertainty analysis into the results.

Techno-economic analysis is helpful in identifying pathways that have great potential of producing economically competitive end products. It also assists in understanding cost structure and thus guiding research efforts to effectively reducing costs ...


An Economic Comparison Of High Moisture Feedstock Biofuel Production, Mitchell J. Amundson Jan 2016

An Economic Comparison Of High Moisture Feedstock Biofuel Production, Mitchell J. Amundson

Graduate Theses and Dissertations

This study compares final fuel production costs of multiple biomass-to-liquid production facilities. Process economics are estimated for four different high moisture feedstocks, four different biomass supply chain pathways and three different conversion and upgrading technologies. Two biorefinery capacities are examined, small (200 tonne per day) and large (2000 tonne per day). Corn stover, corn silage giant miscanthus and sweet sorghum are the feedstocks considered for conversion via hydrothermal liquefaction (HTL) and anaerobic digestion (AD). Final product finishing is done by hydroprocessing of the HTL biocrude and either Fischer-Tropsch (FT) synthesis or methanol-to-gasoline (MTG) conversion of the AD biogas. Water footprints ...


Experimental Study Of The Flow Of Ferrofluid In A Porous Media Under A Magnetic Field, Muskaan Khurana Jan 2016

Experimental Study Of The Flow Of Ferrofluid In A Porous Media Under A Magnetic Field, Muskaan Khurana

Dissertations, Master's Theses and Master's Reports

This research presents results from a laboratory-scale experimental setup that was designed to visualize the behavior of ferrofluid percolation through a porous media. Ferrofluids are colloidal suspensions made of magnetic particles of a few nanometers and stabilized in carrier liquids like water or mineral oil. Ferrofluids get magnetized and align themselves in the direction of a magnetic field when a field gradient is applied.

With the help of this experiment we investigate the viability of controlling fluid flow in porous medium by a magnetic field in vicinity. The experiments show that ferrofluids can be used as a transporting media to ...


An Investigative Analysis Of An Advanced Trim And Respond Control Strategy For Variable Air Volume Hvac Systems, Nicholas Haberl Jan 2016

An Investigative Analysis Of An Advanced Trim And Respond Control Strategy For Variable Air Volume Hvac Systems, Nicholas Haberl

Graduate Theses and Dissertations

Energy efficiency, particularly HVAC energy use in buildings, offers a large potential of reducing overall energy consumption. By optimizing fan controls in variable air volume (VAV) HVAC systems, up to 30 to 50% of fan energy can be saved using trim and respond (TR) strategies compared to constant pressure strategies. The tiered trim and respond (TTR) strategy has shown promise in realizing significant fan energy savings in real buildings without issues of static pressure oscillation.

This study proposed the demonstration of the TTR strategy at five Iowa Army National Guard facilities comparing against fixed static pressure (FSP) and traditional TR ...


Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana Jan 2016

Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana

Open Access Theses & Dissertations

ANSYS Fluent was used to optimize components of a direct power extraction combustor. This includes the fuel injector, nozzle, and cooling units. Changes in the injector's inlet location impacted pressure and velocity distribution. An angle of 115 degrees with respect to the x-axis was found to increase distribution efficiency. Temperature and velocity data from the combustor and nozzle were calculated using NASA CEA and Fluent. Magnitudes of temperature and velocity for CEA and Fluent matched within 9% and 4%, respectively. For the cooling system it is expected that cavitation will not occur since the saturation temperature of water is ...