Mechanical Engineering Commons^™

Mechanical Simulation Of Articular Cartilage Based On Experimental Results, Kevin Matthew Stewart

Master's Theses

Recently, a constituent based cartilage growth finite element model (CGFEM) was developed in order to predict articular cartilage (AC) biomechanical properties before and after growth. Previous research has noted limitations in the CGFEM such as model convergence with growth periods greater than 12 days. The main aims of this work were to address these limitations through (1) implementation of an exact material Jacobian matrix definition using the Jaumann-Kirchhoff (J-K) method and (2) quantification of elastic material parameters based upon research findings of the Cal Poly Cartilage Biomechanics Group (CPGBG). The J-K method was successfully implemented into the CGFEM and exceeded …

Editorial: Advances In The Dynamics Of Granular Materials, Florin Bobaru, J. S. Chen, Joseph A. Turner

Department of Engineering Mechanics: Faculty Publications

Granular materials exhibit a complex array of phenomena which makes the prediction of their behavior extremely difficult. Granular materials are strongly dissipative and show collective (heap formation, jamming) and size segregation phenomena, and can propagate surface waves. They display fluidization and convective motion, and under certain vibration regimes, they tend to mix when they would otherwise segregate, and segregate when they might otherwise mix. The wide range of behaviors that granular materials can display has been one of the main factors for which the development of predictive models has continued to remain an open problem.
The papers in this Special …

Guidance Directrix Generation Using Laser Sensors, Santosh Pitla, Joe D. Luck, Scott A. Shearer

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

A sensor array consisting of two laser sensors was utilized to determine the guidance directrix (offset distance-d, heading angle-ø) that are required as reference inputs for an automated guidance system. The sensor array was evaluated in both laboratory and field conditions. Under laboratory conditions the sensor array replicated the physical profile of the target surface with a 4% error in determining the heading angle. Field tests were conducted in two types of crops; corn and alfalfa. The sensor array identified the cut-crop edge profile ahead of the tractor and replicated distinct shapes of the cut-crop edge. RMSE values in determining …

Dynamics And Control Of Cable-Drogue System In Aerial Recovery Of Micro Air Vehicles Based On Gauss's Principle, Liang Sun, Randal W. Beard, Mark B. Colton, Timothy W. Mclain

Faculty Publications

This paper presents a new concept for aerial recovery of Micro Air Vehicles (ARMAVs) using a large mothership and a recovery drogue. The mothership drags a drogue attached to a cable and the drogue is controlled to match the flight patten of the MAV. This paper uses Gauss’s Principle to derive the dynamic model of the cable-drogue systems. A controllable drogue plays a key role in recovering MAVs in windy conditions. We develop a control approach for the drogue using its drag coefficient. Simulation results based on multilink cable-drogue systems present the feasibility of the aerial recovery concept and the …

Pressure-Driven Transport Of Particles Through A Converging-Diverging Microchannel, Ye Ai, Sang W. Joo, Yingtao Jiang, Xiangchun Xuan, Shizhi Qian

Mechanical Engineering Faculty Research

Pressure-driven transport of particles through a symmetric converging-diverging microchannel is studied by solving a coupled nonlinear system, which is composed of the Navier–Stokes and continuity equations using the arbitrary Lagrangian–Eulerian finite-element technique. The predicted particle translation is in good agreement with existing experimental observations. The effects of pressure gradient, particle size, channel geometry, and a particle’s initial location on the particle transport are investigated. The pressure gradient has no effect on the ratio of the translational velocity of particles through a converging-diverging channel to that in the upstream straight channel. Particles are generally accelerated in the converging region and then …

Me-Em Enewsbrief, June 2009, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Carbon Fiber Leaf Springs For Adaptive Cross Country Skiing, William Drew Atkinson

Master's Theses

This work describes the development of a custom sit ski for US Ski Team paralympian Greg Mallory from concept through prototype fabrication. The ski consists of a custom seat molded specifically for the athlete, carbon fiber leaf springs, and a custom binding attachment system compatible with NNN style cross country bindings. The sit ski is designed to maximize poling power through the use of an upright rather than reclined seating position, allowing for increased utilization of core muscle strength. The springs were designed based on information gathered by a custom National Instruments data acquisition system, and stiffness analysis was conducted …

Simulation Of An Oxidizer-Cooled Hybrid Rocket Throat: Methodology Validation For Design Of A Cooled Aerospike Nozzle, Peter Alexander Brennen

Master's Theses

A study was undertaken to create a finite element model of a cooled throat converging/diverging rocket nozzle to be used as a tool in designing a cooled aerospike nozzle. Using ABAQUS, a simplified 2D axisymmetric model was created featuring only the copper throat and stainless steel support ring, which were brazed together for the experimental test firings. This analysis was a sequentially coupled thermal/mechanical model. The steady state thermal data matched closely to experimental data. The subsequent mechanical model predicted a life of over 300 cycles using the Manson-Halford fatigue life criteria. A mesh convergence study was performed to establish …

Heterogeneous Flow Structure And Gas-Solid Transport Of Riser, Jun You

Dissertations

This study aims to understand physical mechanisms of gas-solid transport and riser flow, investigate heterogeneous flow structures of gas-solid transport and their formation mechanism of the in riser flows, both in axial and radial directions. It provides sound interpretation for the experimental observation and valuable suggestion to riser reactor design. Chemical reaction is also coupled with flow hydrodynamics to board the industrial applications. This study mainly focuses on mathematical modeling approach based upon physical mechanism, and endeavor to validate model prediction against available experimental data.

First of all, most important physical mechanisms including inter-particle collision force, gas/solid interfacial force and …

Frequency Response Of The Skin On The Head And Neck During Production Of Selected Speech Sounds, Jacob B. Munger

Theses and Dissertations

Vibration within the vocal tract during speech is transmitted through body tissue to the skin surface and can be used to transmit speech. Achieving quality speech signals using skin vibration is desirable but problematic, primarily due to the different sources of sound during speech. The objective of this study was to characterize the frequency content of speech signals at various locations on the head and neck. Signals were recorded using accelerometers attached to 15 locations on the heads and necks of 14 males and 10 females as well as a microphone to record audible speech. The subjects produced several isolated …

Mechanics-Based Model For Non-Affine Swelling In Perfluorosulfonic Acid (Pfsa) Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson

Mechanical Engineering Faculty Publications

A mechanics-based model is developed to predict the swelling pressure in perfluorosulfonic acid (PFSA) ionomer membranes during water uptake. The PFSA membrane is represented as a two-phase system, where the water-filled hydrophilic domains are dispersed throughout the hydrophobic polymer matrix. Two representative volume elements (RVEs) are used to represent the nanostructure: (i) a spherical RVE with a spherical hydrophilic domain at the center, and (ii) a cylindrical RVE with a cylindrical hydrophilic domain. The model starts with the non-affine swelling behavior of the membrane and interprets this as a structural reorganization of the RVEs to characterize the microscopic deformation. Swelling …

Tobacco Mosaic Virus Templated Synthesis Of One Dimensional Inorganic-Polymer Hybrid Fibres, Jianhua Rong, Fiona Oberbeck, Xinnan Wang, Xiaodong Li, Jerry Oxsher, Zhongwei Niu, Qian Wang

Faculty Publications

Inorganic–polymer hybrid nanofibres were prepared by using a rod-like tobacco mosaic virus (TMV) as a template. With tetraethylorthosilicate (TEOS) as a precursor, long silica-coated TMVfibres were formed via a head-to-tail assembly, which showed a substantial increase of the elastic modulus. Furthermore, homogenous titania–TMV hybrid fibres could be prepared using polyaniline-coated TMV fibres as a template, which were used to form a composite film that was able to sense liquefied petroleum gases.

The Effective Slip Length And Vortex Formation In Laminar Flow Over A Rough Surface, Anoosheh Niavarani, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The flow of viscous incompressible fluid over a periodically corrugated surface is investigated numerically by solving the Navier–Stokes equation with the local slip and no-slip boundary conditions. We consider the effective slip length which is defined with respect to the level of the mean height of the surface roughness. With increasing corrugation amplitude the effective no-slip boundary plane is shifted toward the bulk of the fluid, which implies a negative effective slip length. The analysis of the wall shear stress indicates that a flow circulation is developed in the grooves of the rough surface provided that the local boundary condition …

Optimization And Stress Analysis Of A Single Stage Rotary Compressor Shaft, Arjunkumar Tummuri

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Arjunkumar Tummuri May 5, 2009.

Enhancing Engine Block Quality By Reducing Metal Chips In Porosities - A Case Study, Santosh Kumar Kurella

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Santosh Kumar Kurella on March 25, 2009.

Design Optimization Of The Rolling Piston Type Rotary Compressor, Pavankumar Kurmagadda

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Pavankumar Kurmagadda May 5, 2009.

Performance Analysis Of Coal-Fired Boiler And Natural Gas Fired Boiler At Morehead State University, Devender Banne

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Devender Banne on May 4, 2009.

Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman

Graduate School of Oceanography Faculty Publications

This paper presents an overview and initial testing results for a shallow water Lagrangian float designed to operate in coastal settings. The presented effort addresses the two main characteristics of the shallow coastal environment that preclude the direct of use of many successfully deep water floats, namely the higher variation of water densities near the coast compared with the open ocean and the highly varied bathymetry. Our idea is to develop a high capacity dynamic auto-ballasting system that is able to compensate for the expected seawater density variation over a broad range of water temperatures and salinities while using measurements …

An Experiment On Integrated Thermal Management Using Metallic Foam, Derek M. Geiger

Master's Theses

This report details an approach to using metal foam heat exchangers inside an integrated thermal management system on a variable cycle engine. The propulsion system of interest is a variable cycle engine with an auxiliary, variable flow rate fan. The feasibility of utilizing an open-celled metallic foam heat exchanger in the ducting between the constant and variable-fans on this variable cycle engine to cool the avionics was explored using an experimental approach. Two heat exchangers, 6.3 inch width by 6.3 inch length by 0.5 inch thickness, were constructed from 20 and 40 pores per inch (PPI) metal foam and tested. …

Numerical Implementation Of Prandtl’S Lifting-Line Theory And Modeling Of Aircraft Take-Off Phase For Wing Optimization, John William Dykes

Honors Capstones

No abstract provided.

An Examination Of Boiler Failures And Associated Design Issues, Tiffany Sherrell Grant

Masters Theses and Doctoral Dissertations

The purpose of this study was to determine if common boiler failures were mainly due to uncontrollable events or from the effects from selecting lower grade materials and processes for the components. Eighteen case studies of tubing failures were selected and examined from boilers all around the world. Twelve of the tubes failed due to excess hoop stress and six failed from some kind of cracking. Calculations were made and it was determined that seventy-five percent of the failures would not have happened if a higher grade but more expensive material had been used. It was also found that 83.3 …

Automated Flight Through Inertial Navigation And Digital Fly-By-Wire Systems, Aaron French

Mechanical Engineering Undergraduate Honors Theses

With technology advancing by leaps and bounds by the year, the uses of Unmanned Aerial Vehicles are becoming more apparent. The possibilities for an aerial vehicle that is fully autonomous are endless. Such aerial vehicles could divert manpower to humanitarian efforts, airlift, and other non‐attack operations. Leaders can put their focus elsewhere on the battlefield with the knowledge that the skies over their heads will be well guarded. These desires give life to projects such as this. No advancement in civilization has ever been made without the collective revolutionary research of great minds, trial by fire, and daring to dream.

Free Fridays: An Alternative Way To Conserve Energy, Lauren Kuenzel

Mechanical Engineering Undergraduate Honors Theses

In February 2007, the University of Arkansas at Fayetteville (UAF) signed the President's Climate Commitment to set a goal of becoming climate neutral. A large part of any strategy to become climate neutral includes energy conservation. In light of that, a four-day school week is proposed for UAF as an alternative energy savings possibility. This reduced schedule has been applied to K-12 schools and state government institutions, but not yet to universities. Along with numerous benefits such as energy conservation of buildings on the free day, a more effective use of time and building space and the positive emotional repercussions …

Nickel-Induced Crystallization Of Amorphous Silicon, Robert Fleming

Mechanical Engineering Undergraduate Honors Theses

One- and two-dimensional silicon nanostructures, such as nanodots, nanowires, and surface topography, have potential uses in a variety of fields, including microelectronics, photonics, and tribology. In this thesis research, nickel-induced crystallization (NIC) of amorphous silicon (a-Si) was investigated to determine the suitability of NIC of a-Si to produce silicon nanostructures on silicon substrates. The results show that formation of both surface topography and nanowires is possible with NIC of a-Si. In addition, the formation of nanostructures is very sensitive to Ni thickness, and the resulting nanostructures and films display a high degree of repeatability. The results obtained from this research …

Design Of A "Figure-8" Spherical Motion Flapping Wing For Miniature Uav's, Zohaib Parvaiz Rehmat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hummingbirds and some insects exhibit a Figure-8 motion, which allows them to undergo variety of maneuvers including hovering. It is therefore desirable to have flapping wing miniature air vehicles (FWMAV) that can replicate this unique wing motion. In this research, a design of a flapping wing for FWMAV that can mimic Figure-8 motion using a spherical four bar mechanism is presented. To produce Figure-8 motion, the wing is attached to the coupler point of the spherical four bar mechanism and driven by a DC servo motor. For verification of the design, a prototype of the wing and mechanism is fabricated …

Thermodynamic, Heat Transfer Analysis And Simulation Of A Domestic Size, Double Stage, Lithium Bromide Absorption System, Carlos R. Lima

Theses and Dissertations - UTB/UTPA

The research presented in this thesis provides an investigation into the thermodynamic and heat transfer requirements for a, 3 ton, Water / Lithium-Bromide absorption system. Thermodynamics results for one stage and two stages absorption system are presented. Heat transfer principles provided a design guideline. Flat-plate, solar, water heaters and auxiliary devices using natural gas were analyzed as the main sources for energy inputs into the generator. Experimental data from the solar collector is provided under several configurations. A TRNSYS simulation of the overall absorption, cooling systems and its alternative energy means provided different scenarios where heating loads into the generator …

Experimental Evaluation And Modeling Of Engine Driven Heat Pump, Isaac Y. Mahderekal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Recently, the Gas Engine-Driven Heat Pump (GHP) System has become an economic choice and more attractive climate control system than the conventional air conditioner due to its advantage in reducing fossil fuel consumption and environmental pollution. The GHP is a new type of heat pump in which the compressor (the core part) is driven by a gas engine. The GHP typically uses the work produced by the engine to drive a vapor-compression heat pump. At the same time, the waste heat rejected by the engine is used for heating purposes.

To improve the system performance of the GHP, a numerical …

Biology-Inspired Adaptive And Nonlinear Robust Control Of Bauv Using Pectoral-Like Fins, Subramanian Ramasamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aquatic animals have splendid ability to move smoothly through water using variety of oscillating fins. Presently researchers are involved in developing biorobotic autonomous underwater vehicles (BAUVs) which have the ability to swim like marine animals. Multiple oscillating fins (dorsal, caudal, pectoral, pelvic, etc.) can be mounted on BAUVs to generate control forces for propulsion and maneuvering. In this research work, control of the BAUVs using pectoral fins alone is considered. The oscillating pectoral fins produce unsteady periodic forces. The control of motion of an BAUV in yaw and dive planes are considered.

Stability Of Basin-Scale Internal Waves Within The South Arm Of The Great Salt Lake, Joshua David Soelberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The fluid circulation patterns, temperature distributions, and density gradients of the South Arm of the Great Salt Lake were modeled using the Estuary, Lake, and Coastal Ocean Model (ELCOM) from the Centre for Water Research at the University of Western Australia. The effort is part of a research study in conjunction with the United States Geological Survey (USGS) and the Utah Water Research Lab located at Utah State University. The model was simulated for several different cases of salinity gradients over different time periods, using temperature and wind data from 2006. The model is then used to identify factors which …

Demonstration Of A Completely Described Swirling Jet Experiment Used For Numerical Validation, Brandon M. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis demonstrates the standard for the design of an experimental model to be used for numerical validation purposes. It is proposed that numerical models may be assessed more accurately and directly by validation with a completely described experimental model, consisting of accurate descriptions of the operating conditions, fluid properties, and experimental uncertainties. This idea is demonstrated using an experimental model of a swirling jet at three Reynolds numbers (Re = 550, 2560, and 3650), with vortex breakdown existing in the higher two Reynolds number cases. Measurements of the swirling jet were obtained at two locations upstream of the jet …