Mechanical Engineering Commons^™

Bi-Directional Variable Stiffness Magnetorheological Elastomer (Mre) Design, Sarah S. Trabia

College of Engineering: Graduate Celebration Programs

What is MRE?
•MRE is a semi-active silicon with embedded iron particles for variable stiffness changes under external magnetic flux

Research Objective
•Feasibility of using MRE as a haptic feedback device.
•Design a MRE device that can increase or decrease the stiffness.
•Design an effective way of providing a “pre-strain” to the base silicon material.

Computational Simulation
•COMSOL 4.3b Finite Element Analysis
•2D axisymmetric model
•Parametric sweep was run to find the amount of current needed to counteract the permanent magnet.

Investigation Of Phase Change In A36 Steel As A Result Of High Velocity Impact Loading, Mena Slewa

College of Engineering: Graduate Celebration Programs

High velocity projectiles cause severe damage to target materials upon impact. The target material is subject to high pressure and temperature over a very short period of time. This work studies the effects of Lexan projectiles impacting A36 steel at velocities between 3 km/sec and 6 km/sec. The damage zone develops in the target within 5 microseconds. Some steel materials go through a reversible phase change when subject to elevated temperature and high quasi-static pressure. It is unknown whether A36 steel experiences this phase change during high velocity impact. The objective of this work is to investigate if any permanent …

Computational Feasibility Study Of Dual Photon/Neutron Imaging Technique, Jessica Hartman, Alexander Barzilov

College of Engineering: Graduate Celebration Programs

• Non-destructive testing (NDT) is crucial for industrial applications, particularly when imaging of internal components or structures is desired

• Current NDT imaging techniques, such as x-rays, focus primarily on isolating unique shapes. Rarely are these methods capable of distinguishing materials or material composition

• Potential application in the car industry for testing and examining the functional durability of products
  − Vehicle engines are composed of a combination of low-z and high-z materials with significant variation in density
  − Being able to determine the location of material during operation eliminates the need to disassemble an engine during study

Plastic Deformation Of Steel Plates Under High Impact Loading, Brendan O'Toole

NSTec UNLV Symposium

• UNLV Two-stage Light Gas Gun
• Experimental Measurements
• Physical Results of Impact on Target Plates
• Research Objectives
• Computational Analysis Methods
• Material Models used in Computational Analysis
• Simulation Comparison: Crater and Deformation
• Simulation Comparison: Free Surface Velocity
• High Speed Video of Experiments
• Microscopy of Failure Surface: Is Phase Change an Issue?
• Electron Back Scatter Diffraction (EBSD) of Failure Surfaces
• On-going Plans and Future Work

Hydraulic And Thermal Performances Of A High Temperature Ceramic Plate-Fin Heat Exchanger (Pfhe), Vijaisri Nagarajan, Yitung Chen, Qiuwang Wang, Ting Ma

College of Engineering: Graduate Celebration Programs

• Numerical analysis was carried for novel configuration of high temperature PFHE
• Fluid flow and heat transfer properties were studied for various fin configurations
• Ripsaw fin design with thickness of 0.05 mm gives maximum heat transfer with less pressure drop and friction factor
• Validation and parametric study were carried out for all fin configurations

Numerical Characterization Of The Hydrodynamics And Thermal Behavior Of Air Flow In A "Flex-Duct" Air Distribution System, Samad Gharehdaghi, Samir Moujaes

College of Engineering: Graduate Celebration Programs

The aim of this research paper is to compute the hydrodynamic and heat transfer characteristics of the air flow inside a flexible duct used for residential/small commercial buildings. Various new information which manufacturers do not provide usually are produced numerically among which heat transfer coefficient, needed for estimating heat loss, is a principal one. Circulation zones in depressions are found to exist. It is shown that these regions act as an insulator and decrease the heat loss along the duct. The results show that fully developed conditions exist much earlier with regard to the inlet for both hydrodynamic and thermal …

Mono-Sized Sphere Packing Algorithm Development Using Optimized Monte Carlo Technique, Karn Soontrapa, Yitung Chen

College of Engineering: Graduate Celebration Programs

In this research, fuel cell catalyst layer was developed using the optimized sphere packing algorithm. An optimization technique named adaptive random search technique (ARSET) was employed in this packing algorithm. The ARSET algorithm will generate the initial location of spheres and allow them to move in the random direction with the variable moving distance, randomly selected from the sampling range (a), based on the Lennard–Jones potential and Morse potential of the current and new configuration. The solid fraction values obtained from this developed algorithm are in the range of 0.610–0.624 while the actual processing time can significantly be reduced by …

Vulnerability Of Progressive Collapse In Reinforced Concrete Flat-Plate Buildings, Jinrong Liu

College of Engineering: Graduate Celebration Programs

• Progressive collapse is the spread of initial local failure, causing partial or
  even total collapse of a building.
• Flat plate structure is widely used for office and residential buildings.
• There is a large inventory of older flat plate building without continuous slab bottom reinforcement through columns.
• Limited knowledge exists regarding the risk of disproportionate collapse in
  older flat-plates under sudden column removal during abnormal events.
• Reliable mechanical model is needed for structural evaluation.

Numerical Modeling Of High Temperature Bayonet Heat Exchanger And Decomposer For Decomposition Of Sulfur Trioxide, Vijaisri Nagarajan, Yitung Chen, Tzu-Chen Hung, Qiuwang Wang, Valery Ponyavin

College of Engineering: Graduate Celebration Programs

Motivation

• Hydrogen is an attractive energy carrier in the future energy technology.

• Hydrogen is produced from splitting of water through various process namely electrolysis, photo-electrolysis, photo-biological production and thermochemical water-splitting.

• The aim of this study is to numerically investigate fluid flow, heat transfer and chemical reaction in bayonet high temperature heat exchanger and decomposer.

• Parametric studies are performed to achieve maximum decomposition with less pressure drop.

Energy Consumption In Large Wastewater Treatment Plants As A Function Of Wastewater Strength, Timothy Newell, Jacimaria R. Batista, Sajjad Ahmad, Walter Johnson

College of Engineering: Graduate Celebration Programs

Wastewater treatment (WWT) is an energy-intensive process. Strict standards for discharge often require energy intensive advanced treatment technologies. As a result, the number of plants using advanced treatment has increased (Figure 1).

Rising energy costs and concerns about greenhouse gas generation present a major incentive for tracking energy usage of WWT. Energy usage in plant, for instance, typically represents 18 to 30% of the operational budget.

Water efficient fixtures are also increasing loadings of organic matter to plants while lowering or maintaining overall liquid flow. The increased loadings have a significant impact on energy consumption.

Previous work has focused primarily …

Understanding And Optimizing Surfaces And Interfaces In Energy Conversion Devices, Clemens Heske

UNLV Renewable Energy Symposium

This inaugural event is dedicated to showcasing the renewable/sustainable energy projects of UNLV faculty, staff, students, and collaborators, as well as other external projects underway statewide and nationally. The development and utilization of new technologies to protect the environment, achieve energy independence, and strengthen the economy will be explored. Speakers and poster-session presenters will provide further insight to many ongoing projects and innovative research ideas.

Organized by UNLV’s Office of Strategic Energy Programs, the event offers participants the opportunity to learn about energy projects and will encourage networking and collaboration. This symposium is intended for researchers, educators, students, policy makers, …