Mechanical Engineering Commons^™

Design And Analysis Of A Compliant Mechanism Spinal Implant, Eric M. Stratton

Theses and Dissertations

This thesis introduces and presents the modeling of a novel compliant spinal implant designed to reduce back pain and restore function to degenerate spinal disc tissues as well as provide a mechanical environment conducive to healing the tissues. The initial objectives for this device development and the focus of this work are modeling and validation of the force-deflection relationships and stress analysis. Modeling was done using the pseudo-rigid-body model to create a 3 degree of freedom mechanism for flexion-extension (forward-backward bending) and a 5 degree of freedom mechanism for lateral bending (side-to-side). These models were analyzed using the principle of …

Uniaxially-Driven Controlled Biaxial Testing Fixture, Fadi K. Abu-Farha, Marwan K. Khraisheh

Mechanical Engineering Faculty Patents

A uniaxially-driven controlled biaxial testing fixture includes a base, a first coupler mounted to the base, and a load input drive rack mounted for linear movement with respect to the base. A second coupler and a first specimen grip are both mounted to the load input drive rack. Second, third and fourth specimen grips are also mounted for linear movement with respect to the base. First, second and third drive mechanisms connect the load input drive rack to the second, third and fourth specimen grips. Together the four specimen grips are oriented to provide biaxial application of force to a …

A One-Dimensional Finite-Difference Solver For Fully-Developed Pipe And Channel Flows, Doug F. Hunsaker

Utah Space Grant Consortium

An algorithm is developed to solve the fundamental flow cases of fully-developed turbulent flow in a pipe and in a channel. The algorithm uses second-order finite-difference approximations for nonuniform grid spacing and is developed in such a way as to easily facilitate the implementation of several two-equation, Reynolds-Averaged-Navier-Stokes turbulence models. Results are included for the Wilcox 1998 k-ω model.

High Strength And Light-Weight Materials Inspired By The Exoskeleton Of Arthropods, Anette M. Karlsson

Mechanical Engineering Faculty Publications

This work investigates the multiscaled structure and the constitutive behavior of the exoskeleton of arthropods (Japanese beetle) along with the response of biomimicked structures. Image analysis (SEM and TEM) revealed three load-bearing regions comprised of chitin-protein fiber layers orientated parallel to the cuticle surface. The chitin fibers in the exocuticle and mesocuticle are organized in a helicoidal structure (layers stacked with a small rotational angle relative to their adjacent layers). The endocuticle has a distinct pseudo-orthogonal pattern, characterized by a thin transitional helicoidal region inserted between two orthogonal layers. Idealized mechanics based models showed that the pseudo-orthogonal structure redistributes the …

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack was modelled and its operation on biomass syn-gas was investigated. The objective of this work was to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack was modelled using Aspen Plus and considers ohmic, activation and concentration losses. It was validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor U_f and U_a, current density j and steam to carbon ratio STCR were varied and …

Validation Of A Simulation Model For A Combined Otto And Stirling Cycle Power Plant, Jim Mcgovern, Barry Cullen, Michel Feidt, Stoian Petrescu

Conference Papers

A project has been underway at the Technological University Dublin (DIT) to investigate the feasibility of a combined Otto and Stirling cycle power plant in which a Stirling cycle engine would serve as a bottoming cycle for a stationary Otto cycle engine. This type of combined cycle plant is considered to have good potential for industrial use. This paper describes work by DIT and collaborators to validate a computer simulation model of the combined cycle plant. In investigating the feasibility of the type of combined cycle that is proposed there are a range of practical realities to be faced and …

Gate 3 Grid Connection Group Processing Approach:An Analysis, John Leahy

Msc. in Energy Management

The aim of this project is to analyse the Group Processing Approach (the “GPA”) to renewable generator grid connections, and in particular the Gate 3 process which is the latest round of the GPA that is currently being implemented in the Republic of Ireland, to determine if it is the most effective approach for connecting new renewable generation. Gate 3 is the third series of the GPA for connecting renewable generation to the Irish Electricity grid where applications are processed in groups or batches. The size of the Gate 3 has bee capped at 3,900MW with applicants being selected based …

An Investigation Into The Retrofitting Of Air Source Heat Pumps Into Fabric Improved, Detached, Oil Centrally Heated Dwellings In Rural Ireland, Ciara Ahern

Other resources

In Ireland the predominant house type is detached housing which constitutes 43 % of entire stock. 72% of the detached housing stock is rurally located and 68% is heated by fuel oil. 82% of houses in Ireland have a radiator heating system. Detached housing, due to larger size and high surface area to volume ratio, has a greater heat loss per m² than all other house types of the same construction period. It follows that, if a heat pump can be successfully deployed in a house of this type it can be successfully deployed in almost all other house …

Turbine House: A Net-Zero Energy House, Karen E. Hernandez

Renée Crown University Honors Thesis Projects - All

Current use of fossil fuels has raised adverse problems in today’s society. The biggest one of them is the climate change caused by emissions of greenhouse gases. For this reason, renewable energies, or energy flows which are replenished at the same rate as they are used, are needed to reduce carbon emissions in the range of 60-80% by the end of the twenty-first century. [1] Energy used in houses nationwide contributes to 16% of generated greenhouse gas emissions. [3] This large percentage of greenhouse emissions could be reduced by designing and developing energy efficient houses, or net-zero energy houses, such …

Vortex Apparatus And Demonstrations, Said Shakerin

All Faculty Articles - School of Engineering and Computer Science

Vortex flow, from millimeter to kilometer in scale, is important in many scientific and technological areas.1 Examples are seen in water strider locomotion, from industrial pipe flow (wastewater treatment) to air traffic control (safe distance between aircrafts on a runway ready for takeoff) to atmospheric studies.2-5 In this paper, we focus on a particular vortex known as bathtub vortex (BTV). It occurs when water is drained from a hole at the bottom of a container such as a bathtub or a sink under the action of gravity. The vortex has a funnel shape with a central air core, resembling a …

Dynamic Analysis Of Grid Connected Hybrid System Of Pv Panel And Wind Turbines For A Light Commercial Building, Bhavin K. Madhu

Masters Theses and Doctoral Dissertations

No abstract

Design Of A Single Alkaline Fuel Cell Test Bed, James Brunton, David Kennedy, Fergal O'Rourke, Eugene Coyle

Conference Papers

This Research focuses on the design and development of a single alkaline fuel cell test bed facility. The paper also makes reference to problems and solutions encountered during construction that resulted in a more effective fuel cell and operating system. As a sustainable and clean alternative energy option, fuel cell technology has the potential to provide electrical power for stationary and mobile applications. Hydrogen and fuel cell technologies are a viable long term energy solution, but to-date has failed to make a major impact on the energy market. Fuel Cells offer a sustainable energy options that can be cost effective …

Mechanical Milling Of Co-Rich Melt-Spun Sm-Co Alloys, Farhad Reza Golkar-Fard

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Rare-earth, high-energy permanent magnets are currently the best performing permanent magnets used today. The discovery of single domain magnetism in 1950’s ultimately led to the development of nanocomposite magnets which had superior magnetic properties. Previous work has shown that mechanical milling (MM) effectively generates nanoscale structures in Sm-Co-based alloys. MM of more Co-rich, melt-spun Sm-Co alloys (up to the eutectic composition) and the role of initial structure on the milling behavior were investigated.

Sm-Co alloys with compositions of Sm_10.5Co_89.5 and Sm₈Co₉₂ were produced by arc melting, melt-spinning and mechanical milling. X-ray diffraction results showed …

Coupled Dem-Fem For Dynamic Analysis Of Granular Systems In Bending, Kitti Rattanadit

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Characterizing the dynamic behavior of granular materials is one of the great challenges in the mechanics of granular matter. Methods for evaluating the mechanical properties of granular matter have applications in a variety of industries, mining and geotechnical activities, defense and military operations. A coupled 2D Discrete Element Method-Finite Element Method (DEM-FEM) code, called "BobKit", is developed and implemented for analyzing the behavior of a 2D granular layer on top of an elastic beam under deforming (quasi-static) or vibrating (dynamic) of the beam. The explicit time-integration dynamic code is used to simulate quasi-static and dynamic bending of the granular layer …

Hydrogen Separation Membranes, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Technical brief describing hydrogen separation membranes and their potential to reduce cost of hydrogen production and CO₂ separation. Outlines membrane types, commercially available membranes, and new technological developments. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Flying Blanket, Keane Daquioag, Ryan Grable, Eric Reynolds, Kaitlin Spak

Mechanical Engineering

This report contains the design plan for PolyNet Design’s Senior Design Project. The PolyNet Design team comprises four mechanical engineering seniors who created a prototype for Raytheon Missile Systems. The overall goal of this project was to create a system that will launch a blanket from a packaged and folded state to an unfurled state and then securely wrap the blanket around a target. The team began with five initial concepts, and chose the Four-Rod model as their first construction concept. Construction of the Four Rod model evolved through several design iterations. The team tested the final prototype extensively, using …

Cal Poly Sit Ski: Final Report, Marc Bergreen, David Bydalek, Ross Gompertz

Mechanical Engineering

The purpose of this project was to design, build, and test a Sit Ski for the US Adaptive Ski Team. The design is for Mr. Marlon Shepard, a new competitor on the Ski Team, who is in need of a new racing sit ski. Some of the top design priorities include reduced weight, increased rider comfort, and increased durability over existing designs. With these design considerations in mind, our team from Cal Poly designed, built and tested a cross country sit ski in June 2010 at the mechanical engineering senior project expo. The project was sponsored by a National Science …

Design And Analysis Of A Low Temperature Co-Fired Ceramic Micro Combustor, Matthew H. Mccrink

Boise State University Theses and Dissertations

This thesis details the design and construction of a Low Temperature Co-Fired Ceramic (LTCC) micro combustion system. The design of the combustor requires a detailed analysis of the flame’s operational properties and stability. To this end, an analytic model was created to address these concerns. These results were used in conjunction with a detailed numerical analysis to determine the stable operating range of the combustors. The combustion of gaseous fuels requires a device with a lower bound on the channel feature size. This lower limit for combustion corresponds to the minimum quenching distance of the specific fuel being used and …

Effects Of Temperature And Humidity On Glass-Reinforced Nylon Rotating Bands, Marc D. Raby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain 30mm munitions used in various military applications are configured with a glass-reinforced nylon band that acts as a firing ring or rotating band. The purpose of this research is to investigate whether storage environments compromise the strength and integrity of the glass-reinforced nylon rotating bands by researching the environmental factors that will degrade nylon and by performing tests to investigate if these factors will embrittle nylon composites. Moisture and temperature are found to be the environmental factors that will have an effect on the rotating bands in their respective storage environments. Absorbed moisture is found to increase the impact …

Evaluation Of Quasi-Static Indentation Damage In Aluminum Honeycomb Core - Graphite/Epoxy Sandwich Structures, David Eisenberg

Renée Crown University Honors Thesis Projects - All

Sandwich composites utilize a low density core and relatively stiff face sheets. These structures are ideal for applications that require high compressive strength, high bending stiffness, and very low weight such as aerospace vehicles. However, one problem with sandwich composites is their susceptibility to low velocity impact damage. Low velocity impacts result in both external damage, in the form of dents, and internal damage, in the form of core crushing, face sheet delaminations (two adjacent plies separating from one another), fiber fractures and matrix cracks. In general, it is assumed that visibly evident damage will be repaired. Barely visible impact …

Thermal Analysis Of Railroad Bearings: Effect Of Wheel Heating, Lariza A. Navarro

Theses and Dissertations - UTB/UTPA

Catastrophic bearing failure is a major concern for the railroad industry because it can lead to costly train stoppages. Excessive heat buildup within the bearing is one of the main factors that can warn of impending failure. The work presented in this thesis is motivated by the need to understand the heat transfer paths to the bearing when wheel heating occurs. A series of experiments and finite element analyses were conducted in order to quantify the different heat transfer mechanisms, with emphasis on radiation. The results indicate that the effect of thermal radiation is minimal when the wheel tread temperature …

Modeling The Momentum And Mass Transfer Within A Micro-Scale Polymer Electrolyte Membrane Fuel Cell For Flows Within The Slip Flow Regime, Sean Tamarun Goudy

Dissertations

Polymer Electrolyte Membrane (PEM) fuel cell systems are heterogeneous catalytic systems. Although there are many computational models that describe the behavior of PEM fuel cells, few simulate the catalyst surface concentration of reactant gases at the catalyst layer-membrane layer inteface. Most PEM fuel cell models make no distinction between the bulk concentration of reactants and the catalyst surface concentration of reactants. It is the surface concentration that is key when studying PEM fuel cell systems: the reactions occur at the surface of the catalyst.

In addition, few model the dynamics within the non-continuum flow region near the solid surfaces of …

Optimum Failure Truncated Testing Strategies, Erik Kostandyan

Dissertations

Accumulated fatigue damage on mechanical components due to random stress loads eventually causes failure. Therefore products with lower failure rates are more desirable. Testing mechanical components for their intended purpose under predetermined working conditions is a common practice used by industries to prevent failures. Fatigue tests are categorized as Time Truncated or Failure Truncated, known in the literature as Type I and Type II tests, respectively. In failure truncated tests, the mechanical components are tested until the desired number of results is obtained. The parameters of a typical failure truncated test include the capacity of the test facility, the actual …

Design And Scale-Up Of Production Scale Stirred Tank Fermentors, Ryan Z. Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the bio/pharmaceutical industry, fermentation is extremely important in pharmaceutical development, and in microbial research. However, new fermentor designs are needed to improve production and reduce costs of complex systems such as cultivation of mammalian cells and genetically engineered micro-organisms. Traditionally, stirred tank design is driven by the oxygen transfer capability needed to achieve cell growth. However, design methodologies available for stirred tank fermentors are insufficient and many times contain errors. The aim of this research is to improve the design of production scale stirred tank fermentors through the development of dimensionless correlations and by providing information on aspects of …

Experimental And Numerical Analysis Of Structures With Bolted Joints Subjected To Impact Load, Kumarswamy K. Nakalswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The aim of this study is to analyze the transient behavior of structures with bolted joints subjected to impact or shock loads using experimental methods and Finite Element Analysis (FEA). Various factors that affect the response of the bolted joint structures for shock loading were studied, such as damping, preload, intensity of impact load and type of FE modeling. The objective of this work was to develop computational modeling procedures that provide structural analysts an improved physics-based shock model for combat vehicles focusing mainly on shock transmission across bolted joints. There is only a limited amount of published literature describing …

Mechanical Behavior Of Alloy 230 At Temperatures Relevant To Ngnp Program, Sudin Chatterjee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Identification and selection of suitable structural materials for heat exchanger application within the purview of the next generation nuclear plant (NGNP) program constitute a major challenge. This challenge stems from the lack of many desired metallurgical and mechanical properties of conventional metallic materials and alloys for applications at temperatures approaching 950 oC. Nickel (Ni)-base Alloy 230 has been highly recommended as a suitable structural material for such application due to its excellent resistance to high-temperature plastic deformation and superior corrosion resistance in many hostile environments. Systematic studies on tensile, fracture toughness, creep, stress-rupture and creep-fatigue behavior of this alloy have …

Catheter Laser Drill, Brady Haug

Industrial Technology and Packaging

The project that I have undertaken is to improve upon an existing machine and process at Applied Medical, a medical device company. The machine is used to drill four holes into the body of a catheter. The holes are located on a linear axis, rotated 90 degrees apart from each other. Currently, the machine utilizes a traditional drill bit to create the four holes. This creates burrs along the holes, which increases the manufacturing time because a worker must remove them. The project calls for the use of a laser to replace the drill bit. The machine designed through this …

Development Of Hydrogen Direct Injection For Conversion Of Internal Combustion Engines, Maxwell A. Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The trend toward usage of vehicles that operate on alternative, renewable forms of energy storage has generated areas for development of new products that will facilitate implementation of new automotive fuel systems. As the reality of a hydrogen-fueled economy emerges, intermediate technologies may be necessary for the transition between hydrocarbon fueled internal combustion engines and hydrogen powered fuel cells. The University of Nevada Las Vegas Center for Energy Research has developed a method for converting the common hydrocarbon fueled internal combustion engine to hydrogen direct injected fueling. This thesis describes the second phase of development and involves the design, fabrication …

Gas-Assisted Powder Injection Molding: A Comparison Of Residual Wall Thickness Between Metal Cavity Vs. Sla Cavity And Effect Of Mold Temperature On Residual Wall Thickness, Donghan Kim

Theses and Dissertations - UTB/UTPA

The effects of processing variables on gas penetration depth and Residual Wall Thickness (RWT) in an aluminum (Al) cavity of Gas-Assisted Injection Molding (GAIM) were investigated with Polypropylene (PP) and Stainless Steel Powder Feedstock (SSPF). The selected processing variables were melt temperature, shot size, gas pressure, and gas delay time. By using a Taguchi L9 array, the results were compared with previous work. For PP, there were no significant differences on gas penetration depth. However, the significance of gas delay time was relatively higher in an Al cavity as compared to a Stereolithography (SLA) cavity from previous work with SSPF. …

An Information Technology Suitability Index For Mass Customization, Oscar Leonardo Barrenechea

Theses and Dissertations - UTB/UTPA

In today’s manufacturing world, high competitive markets are pushing companies to find better ways to satisfy their customer’s needs using several Mass Customization (MC) approaches. Consequently, new Information Technologies (IT) have taken a very important role in order to manage the increasing amount of data generated from those customers. The purpose of this thesis is to develop an IT suitability index for MC that would help to identify the critical IT factors to be addressed in order to efficiently support MC. A linear programming regression model was utilized to generate index values. Finally, the results of this model could be …