Mechanical Engineering Commons^™

Remote Analysis Of Grain Size Characteristic In Submarine Pyroclastic Deposits From Kolumbo Volcano, Greece, Clara Smart, D. P. Whitesell, Christopher N. Roman, Steven Carey

Graduate School of Oceanography Faculty Publications

Grain size characteristics of pyroclastic deposits provide valuable information about source eruption energetics and depositional processes. Maximum size and sorting are often used to discriminate between fallout and sediment gravity flow processes during explosive eruptions. In the submarine environment the collection of such data in thick pyroclastic sequences is extremely challenging and potentially time consuming. A method has been developed to extract grain size information from stereo images collected by a remotely operated vehicle (ROV). In the summer of 2010 the ROV Hercules collected a suite of stereo images from a thick pumice sequence in the caldera walls of Kolumbo …

Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert

Graduate School of Oceanography Faculty Publications

Efficiently profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. Current solutions, such as CTD tow-yos, moving vessel profilers, and undulating tow bodies, are limited by ship speed or water depth. As a consequence, it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales over the deeper sections of the water column. This paper presents a new concept for a profiling vehicle that slides up and down a towed wire in a controlled manner using the lift created by wing foils. The wings …

Energy-Based Analysis Of Utility Scale Hybrid Power Systems, Kwame Agyenim-Boateng

UNLV Theses, Dissertations, Professional Papers, and Capstones

The promise of large-scale use of renewables such as wind and solar for supplying electrical power is tempered by the sources' transient behavior and the impact this would have on the operation of the grid. Among the methods cited for addressing some of those concerns are exploring the complementary nature of solar and wind power generation, and through the use of supplemental energy storage. While the technology for the latter has not been proven to be economical on a large scale at the present time, some assessments of what magnitude is required can be made. An energy-based analysis of utility …

Quantification Of Stochastic Uncertainty Propagation For Monte Carlo Depletion Methods In Reactor Analysis, Quentin Thomas Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Monte Carlo method provides powerful geometric modeling capabilities for large problem domains in 3-D; therefore, the Monte Carlo method is becoming popular for 3-D fuel depletion analyses to compute quantities of interest in spent nuclear fuel including isotopic compositions. The Monte Carlo approach has not been fully embraced due to unresolved issues concerning the effect of Monte Carlo uncertainties on the predicted results.

Use of the Monte Carlo method to solve the neutron transport equation introduces stochastic uncertainty in the computed fluxes. These fluxes are used to collapse cross sections, estimate power distributions, and deplete the fuel within depletion …

Modeling Of A Novel Solar Down Beam Test Facility Utilizing Newtonian Optics, Ryan J. Hoffmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

As advances in concentrated solar energy progress there will inevitably be an increase in the demand of resources for testing new conceptions. Currently, there are limited facilities available for taking concentrated solar energy concepts from the laboratory bench scale to the engineering test scale. A proposed solution is a scientific and developmental facility that provides highly concentrated solar energy at ground level. The design presented is a solar down beam test facility utilizing a Newtonian optics approach with a flat rectangular down beam mirror to reflect and concentrate the sun's rays at ground level.

Literature review suggests a hyperbolic reflector …

Fenestration Studies On Building Energy Using The Facade Evaluation Facility, Wendell Cocina

UNLV Theses, Dissertations, Professional Papers, and Capstones

The project was developed to assess several types of facades and their influence on building energy, mainly focused on windows and other building fenestrations. Requirements for the facility are stated in this paper alongside corresponding solutions. The facility is designed to represent a section of a building façade. Experimenting on a wide range of fenestrations including windows with integrated PV elements was the primary prerequisite. The option of removable façade configurations was used and allowed testing specimens to be changed effortlessly. Instrumentation and data acquisition are discussed including calibration and uncertainty analysis. Investigation of the air conditioning unit was concluded …

Nonlinear Progressive Wave Equation For Stratified Atmospheres, B. Edward Mcdonald, Andrew A. Piacsek

All Faculty Scholarship for the College of the Sciences

The nonlinear progressive wave equation (NPE) [McDonald and Kuperman, J. Acoust. Soc. Am. 81, 1406–1417 (1987)] is expressed in a form to accommodate changes in the ambient atmospheric density, pressure, and sound speed as the time-stepping computational window moves along a path possibly traversing significant altitude differences (in pressure scale heights). The modification is accomplished by the addition of a stratification term related to that derived in the 1970s for linear range-stepping calculations and later adopted into Khokhlov-Zabolotskaya-Kuznetsov-type nonlinear models. The modified NPE is shown to preserve acoustic energy in a ray tube and yields analytic similarity solutions for …

2011 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

The Fall 2011 ENGR333 project focused on the Bunker Interpretive Center (BIC) at Calvin University.

I asked the students “What would it take for Calvin College to obtain an Energy Star rating for the BIC? Or, if the BIC already qualifies for an Energy Star rating, what would it take to improve the energy efficiency of the BIC (as measured by Energy Star metrics) by 15%, thereby ensuring Energy Star performance of the building into the future?”

Customer

As I recall, the customer for this project was Biology faculty member Randy Van Dragt.

Time-Dependent Crack Growth Behavior Of Alloy 617 And Alloy 230 At Elevated Temperatures, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two Ni-base solid-solution-strengthened superalloys: INCONEL 617 and HAYNES 230 were studied to check sustained loading crack growth (SLCG) behavior at elevated temperatures appropriate for Next Generation Nuclear Plant (NGNP) applictaions with constant stress intensity factor (K _max = 27.75 MPa[checkmark]m) in air. The results indicate a time-dependent rate controlling process which can be characterized by a linear elastic fracture mechanics (LEFM) parameter - stress intensity factor (K). At elevated temperatures, the crack growth mechanism was best described using a damage zone concept. Based on results and study, SAGBOE (stress accelerated grain boundary oxidation embrittlement) is considered the primary reason for …

A Study On Facility Planning Using Discrete Event Simulation: Case Study Of A Grain Delivery Terminal, Sarah M. Asio

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

The application of traditional approaches to the design of efficient facilities can be tedious and time consuming when uncertainty and a number of constraints exist. Queuing models and mathematical programming techniques are not able to capture the complex interaction between resources, the environment and space constraints for dynamic stochastic processes. In the following study discrete event simulation is applied to the facility planning process for a grain delivery terminal. The discrete event simulation approach has been applied to studies such as capacity planning and facility layout for a gasoline station and evaluating the resource requirements for a manufacturing facility. To …

Astro Camp Presentation, Get Away Special Team 2011

Education and Outreach

No abstract provided.

Perfectly Matched Layer Absorbing Boundary Conditions For The Discrete Velocity Boltzmann-Bgk Equation, Elena Craig

Mathematics & Statistics Theses & Dissertations

Perfectly Matched Layer (PML) absorbing boundary conditions were first proposed by Berenger in 1994 for the Maxwell's equations of electromagnetics. Since Hu first applied the method to Euler's equations in 1996, progress made in the application of PML to Computational Aeroacoustics (CAA) includes linearized Euler equations with non-uniform mean flow, non-linear Euler equations, flows with an arbitrary mean flow direction, and non-linear clavier-Stokes equations. Although Boltzmann-BGK methods have appeared in the literature and have been shown capable of simulating aeroacoustics phenomena, very little has been done to develop absorbing boundary conditions for these methods. The purpose of this work was …

Quantifying Multiple Types Of Damping Acting On Bronze-Wound Guitar Strings, Jonathan Christian

Purdue Polytechnic Masters Theses

The goal of this study was to quantify the contributions of multiple damping types acting on guitar strings for each mode over a wide frequency range so that design variables could be identified to one day create frequency based damping in guitar strings. Structural dynamic testing was used to obtain the time-response of a vibrating string in open air and in a vacuum. From this signal, each harmonic was filtered and the decay envelope was curve-fitted with a function that was a linear summation of decay functions. From the curve-fits, the damping coefficients for aerodynamic, friction, and material damping were …

Development Of A Cubesat Instrument For Microgravity Particle Damper Performance Analysis, John Trevor Abel

Master's Theses

Spacecraft pointing accuracy and structural longevity requirements often necessitate auxiliary vibration dissipation mechanisms.  However, temperature sensitivity and material degradation limit the effectiveness of traditional damping techniques in space.  Robust particle damping technology offers a potential solution, driving the need for microgravity characterization.   A 1U cubesat satellite presents a low cost, low risk platform for the acquisition of data needed for this evaluation, but severely restricts available mass, volume, power and bandwidth resources.  This paper details the development of an instrument subject to these constraints that is capable of capturing high resolution frequency response measurements of highly nonlinear particle damper dynamics.

College Of Engineering Senior Design Competition Spring 2011, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

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 projects on …

College Of Engineering Senior Design Competition Fall 2011, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

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 projects on …

How Much Do U.S. University Students Know, And Want To Know, About Sustainability And Green Building? The Findings Of A Survey, And Possible Implications For General Elective Curricula., Jeremy R. Farner

Purdue Polytechnic Masters Theses

Using the survey approach, this investigation examined the attitudes and interest of college students at two universities in different geographic locations within the United States.  Approximately 24,000 students from all disciplines and majors at Weber State University (WSU) in Utah, and 4,000 at Purdue University in Indiana, were invited to participate in a study to determine current knowledge, familiarity, and interest in topics within the sustainability and Green Building educational arena. The goal of this study was to determine what students already know, would like to know, and how much interest there would be in developing …

Computational Study Of Passive Neutron Albedo Reactivity (Pnar) Measurement With Fission Chambers, Sandra De La Cruz

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Passive Neutron Albedo Reactivity technique (PNAR) was used to assay used nuclear fuel as a potential method for the measurement of fissionable material in fuel assemblies. A Monte Carlo transport code (MCNPX 2.6) was used to develop simulation models to evaluate the PNAR technique. The MCNPX simulated models consisted of two 17x17 Pressurized Water Reactor (PWR) used fuel assemblies; one with an initial 3 wt% uranium-235*, cooled for 20 years and second with an initial 4 wt% uranium-235*, cooled for 5 years. Each used fuel assembly was simulated at four different burn up rates of 15, 30, 45, and …

Effects Of Inlet Conditions On Diffuser Outlet Performance, Zaccary A. Poots

UNLV Theses, Dissertations, Professional Papers, and Capstones

Building air distribution terminal system designers and system installers require accurate quantitative information on the performance of the installed system to achieve optimum efficiency and levels of human comfort. This requires field installation adjustment values from published ideal pressure loss, air distribution and sound generation installation performance. This study documents the air output performance of different installation configurations of six types of ceiling diffusers and compares the results to performance when installed according to ANSI/ASHRAE Standard 70-2006. A diffuser inlet supply plenum was designed for optimum flow and used to acquire a baseline set of data covering the six types …

Development Of High Resolution Sea Floor Mapping Tools And Techniques, Gabrielle Inglis, J. Ian Vaughn, Clara Smart, Christopher N. Roman

Graduate School of Oceanography Faculty Publications

There is a persistent need for high resolution photographic and bathymetric maps of the sea floor for many research areas in marine geology, biology and archaeology. This poster will present recent work using high frequency multibeam sonars, stereo vision and structured light laser imaging techniques to create maps with centimeter resolution for these applications. This research involves the development of new image and sonar processing techniques that combat the typical difficulties of imperfect navigation information, limited sensor ranges and adverse environmental conditions associated with using marine robotic vehicles in the ocean. Data for this work has been collected with the …

Surface Geometry And Heat Flux Effect On Thin Wire Nucleate Pool Boiling Of Subcooled Water In Mictrogravity, Troy Munro, Heng Ban

Presentations

No abstract provided.

Long Term Outdoor Testing Of Low Concentration Solar Modules, Lewis Fraas, James Avery, Leonid Minkin, H. X. Huang, Tim Hebrink, Robert F. Boehm

Mechanical Engineering Faculty Research

A 1‐axis carousel tracker equipped with four 3‐sun low‐concentration mirror modules has now been under test outdoors at the University of Nevada in Las Vegas (UNLV) for three years. There are three unique features associated with this unit. First, simple linear mirrors are used to reduce the amount of expensive single crystal silicon in order to potentially lower the module cost while potentially maintaining cell efficiencies over 20% and high module efficiency. Simple linear mirrors also allow the use of a single axis tracker. Second, the azimuth carousel tracker is also unique allowing trackers to be used on commercial building …

Understanding Industrial Energy Use Through Lean Energy Analysis, Brian Abels, Franc Server, J. Kelly Kissock, Dawit Ayele

Mechanical and Aerospace Engineering Faculty Publications

Due to rising energy costs and global climate change, many industries seek to improve their energy efficiency. This paper describes a three-step method to analyze utility billing, weather, and production data to understand a company’s energy performance over time. The method uses regression modeling of utility billing data against weather and production data. The regression models are then driven with typical weather and production data to calculate the ‘normal annual consumption’, NAC. These steps are repeated on sequential sets of 12 months of data to generate a series of ‘sliding’ NACs and regression coefficients. The method can quantify successful energy …

Multidisciplinary Design Optimization Of Transonic Airfoil Sections Using Multiobjective Optimization And Computational Intelligence Tools, Amit A. Kulkarni

Mechanical & Aerospace Engineering Theses & Dissertations

The design of transonic airfoils for civil aviation applications has been a major engineering challenge in the last fifty years. This design problem arises due to the need to limit shock wave drag at a given transonic speed. In recent years, the requirement to reduce the levels of aircraft noise has started to affect the airfoil design process. The multidisciplinary aerodynamic shape optimization problem is treated in this thesis using a multi-objective approach. The objectives correspond to the design of transonic airfoil sections with low drag during cruise and low trailing edge noise levels during the approach condition. The optimization …

Research On Coupled Human And Natural Systems (Chans): Approach, Challenges, And Strategies, Marina Alberti, Heidi Asbjornsen, Lawrence A. Baker, Nicholas Brozović, Laurie E. Drinkwater, Scott A. Drzyzga, Claire A. Jantz, José Fragoso, Daniel S. Holland, Timothy A. Kohler, Jianguo Liu, William J. Mcconnell, Herbert D. G. Maschner, James D. A. Millington, Michael Monticino, Guillermo Podestá, Robert Gilmore Pontius Jr., Charles L. Redman, Nicholas J. Reo, David J. Sailor, Gerald Urquhart

Mechanical and Materials Engineering Faculty Publications and Presentations

Understanding the complexity of human–nature interactions is central to the quest for both human well-being and global sustainability. To build an understanding of these interactions, scientists, planners, resource managers, policy makers, and communities increasingly are collaborating across wide-ranging disciplines and knowledge domains. Scientists and others are generating new integrated knowledge on top of their requisite specialized knowledge to understand complex systems in order to solve pressing environmental and social problems (e.g., Carpenter et al. 2009). One approach to this sort of integration, bringing together detailed knowledge of various disciplines (e.g., social, economic, biological, and geophysical), has become known as the …

Measuring Progress With Normalized Energy Intensity, Nathan Lammers, J. Kelly Kissock, Brian Abels, Franc Server

Mechanical and Aerospace Engineering Faculty Publications

Energy standard ISO 50001 will require industries to quantify improvement in energy intensity to qualify for certification. This paper describes a four-step method to analyze utility billing, weather, and production data to quantify a company's normalized energy intensity over time. The method uses 3-pararameter change-point regression modeling of utility billing data against weather and production data to derive energy signature equations. The energy signature equation is driven by typical weather and production data to calculate the 'normal annual consumption', NAC, and divided by typical production to calculate 'normalized energy intensity' NEI. These steps are repeated on sequential sets of 12 …

Optimizing Compressed Air Storage For Energy Efficiency, Brian Abels, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

Compressed air storage is an important, but often misunderstood, component of compressed air systems. This paper discusses methods to properly size compressed air storage in load-unload systems to avoid short cycling and reduce system energy use. First, key equations relating storage, pressure, and compressed air flow are derived using fundamental thermodynamic relations. Next, these relations are used to calculate the relation between volume of storage and cycle time in load-unload compressors. It is shown that cycle time is minimized when compressed air demand is 50% of compressor capacity. The effect of pressure drop between compressor system and storage on cycle …

Improving Compressed Air Energy Efficiency In Automotive Plants: Practical Examples And Implementation, Nasr Alkadi, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

The automotive industry is the largest industry in the United States in terms of the dollar value of production [1]. U.S. automakers face tremendous pressure from foreign competitors, which have an increasing manufacturing presence in this country. The Big Three North American Original Equipment Manufacturers (OEMs)-General Motors, Ford, and Chrysler-are reacting to declining sales figures and economic strain by working more efficiently and seeking out opportunities to reduce production costs without negatively affecting the production volume or the quality of the product. Successful, cost-effective investment and implementation of the energy efficiency technologies and practices meet the challenge of maintaining the …

Surface Geometry And Heat Flux Effect On Thin Wire Nucleate Pool Boiling Of Subcooled Water In Microgravity, Troy Munro, Andrew Fassman

Presentations

The motivation of this nucleate boiling research is to understand the effects of surface geometry and heat flux as applied to a thin wire heater. This will further the understanding of the fundamental behaviors of boiling onset, steady state heat transfer, and bubble dynamics with respect to nucleate boiling with the goal of creating efficient thermal management systems for future space applications. Using three different thin platinum wire geometries and five different power levels, subcooled water was boiled over a period of approximately 30 seconds for 15 parabolic arcs to simulate microgravity. To represent the trends in bubbles behavior across …

Effects Of Heat Flux On Nucleate Boiling In Microgravity, Andrew Fassman

Presentations

No abstract provided.