Digital Commons Network^™

A Finite Difference Implementation Of Phase Field Theory, Nicholas W. Oren

Master's Theses

Computationally handling cracks generally results in numerically unstable results. Specifically handling the infinite stresses at the crack tip as well as the abrupt change from virgin material to failed material creates numerical instabilities. This project seeks to determine if phase field physics theory, particularly the physics based modification developed by B. N. Cassenti, can be appropriately applied to cracks. Phase field theory introduces an additional state variable, the phase of the material. The phase represents the level of failure (by cracking), and diffuses the failure along a crack by specified equations. The modification, based on a variational principle, was tested …

Production Of A Banjo: Development Of Manufacturing Processes For Banjo Resonators,Rims, And Necks., Kevin N. Zollinger

Undergraduate Honors Theses

This body of research focused on the development of prototype tooling and manufacturing processes to produce resonators, rims, and necks for building banjos. The resulting fixtures and manufacturing processes were designed for ease of use by a single employee in a small shop environment. This research required proficiency in interdisciplinary mediums (ie. 2D modeling, 3D modeling, centerline tool path program generation, 2D modeling, 3D modeling, rendering, design, and woodworking).

The resonator required development of a matching set of forming surfaces, a bending/gluing fixture, a work-holding fixture for utilizing a wood lathe, and a steam chamber required for bending strips of …

Methods For Identifying Acoustic Emissions From The Front Face Of A Small Piezoelectric Blower, Brad K. Solomon

Theses and Dissertations

This thesis focuses on identifying acoustic noise generating components in piezoelectric blowers through transverse velocity measurements and the development of a numerical fluid model. Piezoelectric ceramics have proven useful for many industries and areas of research involving: high precision actuators, noise control, ultrasonic devices, and many other areas. As of late, a unique adaptation of piezoelectric ceramics is surfacing in the area of pumping and cooling. Air pumps that use these ceramics replace the traditional electric motor, resulting in lower power consumption, less moving parts, constant pressure gradients, lower overall weight, and a low profile. The current drawback of this …

Parametric Study On A Novel Waste Heat Recovery System, Ghaleb Rustom Abdul Sater

Electronic Thesis and Dissertation Repository

The present thesis is based on an industry-sponsor project involving a novel waste heat-to-electricity conversion system. This proprietary system utilizes thermal energy from a low temperature heat sources to produce torque that drives an electric generator to produce electricity. The system needs to be studied through scientific research to help with optimizing the product development, component design, and overall system performance. The main objectives of this study are to develop simulation tools (numerical model) that will allow to simulate the thermo-fluid processes in various system components and to use this numerical model to study the heat transfer and phase-change processes …

Optimal Inertial Sensor Placement And Motion Detection For Epileptic Seizure Patient Monitoring, Babak Kamalizonouzi

Electronic Thesis and Dissertation Repository

Use of inertial sensory systems to monitor and detect seizure episodes in patients suffering from epilepsy is investigated via numerical simulations and experiments. Numerical simulations employ a mathematical model that is able to predict human body dynamic responses during a typical epileptic seizure. An optimized inertial sensor placement procedure is developed to address achievement of highest possible sensing resolution in determining angular accelerations with minimal errors. In addition, a joint torque estimation procedure is formulated to assist in the future development of a possible detection scheme. Experimental motion data obtained from an epileptic seizure patient as well as a healthy …

Development Of A Compact Piezoworm Actuator For Mr Guided Medical Procedures, Khaled El Bannan

Electronic Thesis and Dissertation Repository

In this research, a novel piezoelectric actuator was developed to operate safely inside the magnetic resonance imaging (MRI) machine. The actuator based on novel design that generates linear and rotary motion simultaneously for higher needle insertion accuracy. One of the research main objectives is to aid in the selection of suitable materials for actuators used in this challenging environment. Usually only nonmagnetic materials are used in this extremely high magnetic environment. These materials are classified as MRI compatible materials and are selected to avoid hazardous conditions and image quality degradation. But unfortunately many inert materials to the magnetic field do …

The Effects Of Freestream Turbulence On Serpentine Diffuser Distortion Patterns, Jesse Scott Johnson

Theses and Dissertations

Serpentine diffusers have become a common feature in modern aircraft as they allow for certain benefits that are impossible with a traditional linear configuration. With the benefits, however, come certain disadvantages, namely flow distortions that reduce engine efficiency and decrease engine surge stability margins. These distortions are now being researched comprehensively to determine solutions for mitigating the adverse effects associated with them. This study investigates how varying the freestream turbulence intensity of the flow entering a serpentine diffuser affects the distortion patterns that are produced by the diffuser. Experiments were performed with a model serpentine diffuser on the Annular Cascade …

Experimental Investigation Of The Fluid Temperature Field And The Thermal Performance Of Insert Devices In A Flat-Plate Solar Collector, Gurveer Singh Sandhu

Electronic Thesis and Dissertation Repository

An experimental study on the thermal flow behavior inside a flat-plate collector and the impact of insert devices (passive heat transfer enhancement techniques) on the thermal performance of the collector is presented. Temperature fields were obtained for different Reynolds numbers (250-650) and at different inclination angles of the collector. The results show that a stratified flow is developed inside the collector and the warmer fluid restricts itself to the upper portion of the collector only. Various new configurations of the conventional insert devices were tested over a wide range of Reynolds number (200-8000). Comparison of these devices show that in …

Best Practices Using Building Information Modeling In Commercial Construction, Simon Beveridge

Theses and Dissertations

There has been an increase in adoption of building information modeling (BIM) by commercial contractors over the past few years but there is not a clear indication of current application or the frequency of each use. This research was undertaken to determine the frequency and best practices of using BIM in commercial construction. Leading commercial contracting firms were contacted and employees were selected to complete a telephone survey that was designed to determine how they are using BIM. It was found that BIM is being used with more frequency on projects, with plans to continue to implement it even further …

Vibrotactile Feedback Generation Using Envelope Waveforms And Eccentric-Mass Motors, Michael G. Plooster

Theses and Dissertations

The usefulness of vibrotactile feedback as a channel to communicate information has been widely recognized. However, most of the recent work on this subject uses actuators that are either too expensive or too large for many practical applications. This thesis explores the generation of vibrotacatile feedback patterns using a simple, inexpensive eccentric-mass motor that is constrained to use a constant voltage and a low on/off switching frequency. In particular, it explores the pulse timing method, which utilizes the slow transient response of the eccentric-mass motor to calculate pulse and rest times for an arbitrary envelope waveform shape. Several hardware tests …

Comparison Of 3-D Friction Stir Welding Viscoplastic Finite Element Model With Weld Data And Physically-Simulated Data, Maria Posada

Theses and Dissertations

Models (both physical and numerical) of the friction stir (FS) welding process are used to develop a greater understanding of the influence of independent process parameters on dependent process output variables, such as torque, power, specific weld energy, peak temperature, cooling rates and various metallurgical factors (e.g., grain size and precipitates). An understanding of how the independent process parameters influence output variables and ultimately their effect on resultant properties (e.g., strength, hardness, etc..) is desirable. Most models developed have been validated primarily for aluminum alloys with relatively small amounts of experimental data. Fewer models have been validated for steels or …

Internal Wave Generation Over Rough, Sloped Topography: An Experimental Study, Lauren Elizabeth Eberly

Theses and Dissertations

Internal waves exist everywhere in stratified fluids - fluids whose density changes with depth. The two largest bodies of stratified fluid are the atmosphere and ocean. Internal waves are generated from a variety of mechanisms. One common mechanism is wind forcing over repeated sinusoidal topography, like a series of hills. When modeling these waves, linear theory has been employed due to its ease and low computational cost. However, recent research has shown that non-linear effects, such as boundary layer separation, may have a dramatic impact on wave generation. This research has consisted of experimentation on sloped, sinusoidal hills. As of …

Effective Collaboration Through Multi User Cax By Implementing New Methods Of Product Specification And Management, Vonn L. Holyoak

Theses and Dissertations

This thesis presents a new design process in which design specifications and task distribution are determined from a parallel multi user prospective. Using this method, projects are more easily decomposed into tasks that can be performed concurrently, thus decreasing the design time. Also, a framework is provided to determine the correct distribution of available talent and stakeholders that can be utilized on a given project. The research suggests that by involving the necessary stakeholders in a multi user setting, changes can be made quickly and without additional approval wait time. By including individuals from the various areas of required talent, …

Steam Reheat In Nuclear Power Plants, Paul John Marotta

Doctoral Dissertations

In this work, reheating steam from a commercial nuclear power plant is explored in order to increase efficiency and power output. A thermal source in the form of a High Temperature Gas Reactor (HTGR) is considered. Engineering challenges include proof-of-principle, reactor sizing, evaluation, and feasibility.

The proposed thermodynamic process modifications have been evaluated for a range of inlet steam quality conditions. The evaluation of the steam tube dimensions and number of optimal tubes have been calculated utilizing the so-called Log Mean Temperature Difference method. Subsequently, the performance of the steam tubes was further analyzed within a water vapor and liquid …

Strider: Manufacturing Processes, Michael Warren-Angelucci

Industrial and Manufacturing Engineering

The goal of the Strider Project is to create a mobility device that can support a person with weakened leg strength and enable them to be supported and maintain a standing position. A prototype of the Strider was created by three Mechanical Engineering students as their senior project. The topic of this senior project was to analyze and create a manufacturing process for the manufacture of the Strider that will be ergonomic and cost effective.

There were many things that needed to be accomplished in order to create the manufacturing process. The first step was to verify that the prototype …

Fuzzy Logic Controller For Parallel Plug-In Hybrid Vehicle, Sk. Khairul Hasan

Theses and Dissertations

Hybrid electric vehicles combine two methods for propelling a vehicle. In a parallel hybrid vehicle, the two propulsion methods work in parallel to meet the total power demand. Among different combination of power sources, internal combustion engine and electric motor drive system are the most popular because of their availability and controllability. Plug-in hybrid vehicle is the latest version in hybrid vehicle family. In plug-in hybrid vehicle, battery is directly recharged from the electrical power grid and it can be used for a long distance with higher efficiency. Most of the hybrid vehicles on the road are parallel in nature …

Preventing Sheet Metal Wrinkling In Coil Lines, David Steven Revers

Theses and Dissertations

Coil lines are used in metal packaging facilities to treat the metal before forming the final product. As the sidewalls of cans are becoming thinner and thinner, one can see that the equipment has not been designed properly to feed up lighter plate weight metal. Thinner can walls cause the metal sheet to be fed into the machine crooked and results in a wrinkling of the first few feet of metal, which then needs to be thrown away. Because the current equipment is not working properly, operators have been feeding sheets of metal up a ten-foot ladder into the machine …

Material Behavior Characterization Of A Thin Film Polymer Used In Lithium-Ion Batteries, Michael James Martinsen

Theses and Dissertations

The use of lithium-ion batteries in the automotive industry has become increasingly popular. As more hybrid and electric vehicles take to the road an understanding of how these batteries will behave structurally will be of greater concern. Impact testing can give a valuable overview of the strengths and weaknesses of a battery's design, however, these tests can be time consuming, expensive, and dangerous. Finite element analysis can deliver a reliable low cost approximation of physical testing results. The accuracy of FE results depends greatly on the mathematical representation of the material properties of Li-ion battery components. In this study, the …

Development Of Mems-Based Corrosion Sensor, Feng Pan

Graduate Theses and Dissertations

This research is to develop a MEMS-based corrosion sensor, which is used for monitoring uniform, galvanic corrosion occurring in infrastructures such as buildings, bridges. The corrosion sensor is made up of the composite of micro/nano metal particles with elastomers. The mechanism of corrosion sensor is based on the mass transport of corrosive species through the sensor matrix. When the metal particles in the matrix corrode, the electrical resistivity of the material increases due to increasing particle resistances or reduction of conducting pathways. The corrosion rate can be monitored by detecting the resistivity change in sensing elements. The life span of …

Silica Nanoparticle-Based Coatings With Superhydrophilic And Superhydrophobic Properties, Robert Andrew Fleming

Graduate Theses and Dissertations

Superhydrophilic and superhydrophobic surfaces have potential for implementation into a variety of fields, including self-cleaning surfaces, anti-fogging transparent materials, and biomedical applications. In this study, sandblasting, oxygen plasma treatments, silica nanoparticle films, and a low surface energy fluorocarbon film were employed to change the natural surface wettability of titanium, glass, and polyethylene terephthalate (PET) substrates, with an aim to produce superhydrophilic and superhydrophobic behavior. The effects of these surface modifications are characterized by water contact angles (WCAs), surface wetting stability, surface morphology and roughness, surface elemental composition, and optical transmittance measurements. The results show that stable superhydrophilic and superhydrophobic surfaces …

Distribution Map Of Multi-Walled Carbon Nanotubes In A Refrigerant/Oil Mixture Within A 2.5 Ton Unitary Air-Conditioner, Warren Russell Long

Graduate Theses and Dissertations

In recent years, nanoparticles have received considerable attention as a potential additive to heat transfer fluids (i.e. refrigerant) in order to increase the heat transfer capabilities of these fluids. The potential of carbon nanotubes (CNTs) to exit the compressor, migrate throughout a vapor compression air conditioning system, and possibly foul the components of such a system was experimentally investigated in this research. Six grams of CNTs were dispersed in the polyol ester oil used by a 2.5 ton (8.79 kW) unitary air conditioning system, which was continuously operated for 168 hours. After this time, the unit was shut down and …

High Capacity Lithium-Ion Battery Characterization For Vehicular Applications, Sazzad Hossain Ahmed

Masters Theses

A lithium-ion battery is one of the key research topics in energy storage technologies. Major characterization tests such as static capacity, open circuit voltage (OCV), hybrid pulse power characterization (HPPC) have been conducted on two different chemistries, LiMnNi and LiFePO₄, high capacity lithium-ion batteries over a wide range of temperatures from 50ºC to -30ºC. Detail analysis of temperature effects on battery capacity and simple models of direct current resistance (DCR) increment and power decrement over temperatures have been proposed using the test results. Electrochemical impedance spectroscopy (EIS) tests have been performed to find out the dominant internal resistances …

Computational Fluid Dynamics Investigation Of The Orientation Of A Pediatric Left Ventricle Assist Device Cannula To Reduce Stroke Events, Stephen Guimond

HIM 1990-2015

Ventricle Assist Devices (VADs), which are typically either axial or centrifugal flow pumps implanted on the aortic arch, have been used to support patients who are awaiting cardiac transplantation. Success of the apparatus in the short term has led to long term use. Despite anticoagulation measures, blood clots (thrombi) have been known to form in the device itself or inside of the heart. The Ventricle Assist Devices supply blood flow via a conduit (cannula) implanted on the ascending aorta. Currently, the implantation angle of the VAD cannula is not taken into consideration. Since the VADs supply a significant amount of …

Application Potential Of Solar Pv, Wind And Fuel Cells Technologies For Global Sustainability Improvement, Qiang Zhai

Theses and Dissertations

This dissertation develops a systematic approach to comprehensively investigate the application potential of Solar PV, wind and fuel cells in reducing GHGs emissions for energy intensive global manufacturing industry. This systematic approach is developed by integrating the technological and economic characteristics of the clean energy technologies, as well as the local geographic conditions where the clean energy technologies may be deployed. This approach consists of the investigation on such aspects as: technological feasibility, capacity factor, FIT strength, Levelized energy cost, cost benefit and sensitivity.

In this dissertation, the systematic approach developed is applied on the application potential analyses of solar …

Validation Of Weak Form Thermal Analysis Algorithms Supporting Thermal Signature Generation, Elton Lewis Freeman

Masters Theses

Extremization of a weak form for the continuum energy conservation principle differential equation naturally implements fluid convection and radiation as flux Robin boundary conditions associated with unsteady heat transfer. Combining a spatial semi-discretization via finite element trial space basis functions with time-accurate integration generates a totally node-based algebraic statement for computing. Closure for gray body radiation is a newly derived node-based radiosity formulation generating piecewise discontinuous solutions, while that for natural-forced-mixed convection heat transfer is extracted from the literature. Algorithm performance, mathematically predicted by asymptotic convergence theory, is subsequently validated with data obtained in 24 hour diurnal field experiments for …

Heat Transfer Analysis Via Rate Based Sensors, Jake Erik Plewa

Masters Theses

This work presents an integrated rate-based sensor and method for resolving the surface heat flux of a fundamental inverse heat conduction problem without numerical regularization or differentiation in a semi-infinite geometry that additionally accounts for thermocouple delay due to its intrinsic time constant. The sensor uses well-designed analog filters to directly regularize raw voltage data to eliminate the need for numerical regularization methods. The sensor can also be used in a series of well-designed voltage-rate interfaces that directly measure the voltages from in-depth thermocouples, which are used in conjunction with the thermocouple calibration curve to provide higher-time derivatives of the …

Testing, Analysis, And Model Verification Of Miniature Linear Permanent Magnet Generators, Michael Ray Rippee

Boise State University Theses and Dissertations

The military has become increasingly dependent on mobile electronic equipment to ensure success and safety of soldiers in remote locations. To operate the electronics, soldiers must carry batteries that can weigh up to 12kg (26.5lb). To decrease the load soldiers must carry, a backpack with an internal linear electric generator has been proposed to provide portable power for soldiers on foot. In designing a generator for this purpose, a simulation was developed to predict the power generation capacity of linear permanent magnet generators. This thesis presents work done to experimentally verify the theoretical simulation with a desired accuracy of 20%. …

Investigation Of The Noise Floor Of The Standard Piv Cross-Correlation Algorithm, Kyle L. Jones

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Particle image velocimetry (PIV) is a powerful measurement technique used to acquire instantaneous measurements of entire flow fields at a given instant in time. Quantifying the uncertainty and error in PIV is a critical part of realizing the full potential of PIV as a flow measurement technique.

The noise floor of PIV is the minimum amount of random error that can be achieved for a particular standard cross-correlation (SCC) algorithm. The noise floor of the SCC used by DaVis in correlating image pairs is explored. Two methods for creating image pairs for correlation are compared, namely pseudo image pairs and …

Aerodynamic Analysis And Drag Coefficient Evaluation Of Time-Trial Bicycle Riders, Peter Nicholas Doval

Theses and Dissertations

Evaluation of drag coefficient often requires wind tunnel experiments and can be prohibitively expensive if not impossible for large objects or systems. Computational Fluid Dynamics (CFD) aerodynamic analysis offers an alternative approach and can be used as a very effective design tool in many industries: automotive, aerospace, marine, etc. The main objective of this research is to investigate feasibility of using non-contact digitizers for developing finite element models of large objects for subsequent CFD analysis. The developed methodology is applied to investigation of time-trial bicycle rider efficiency. Companies competing in this class of racing spend millions trying to optimize bicycle …

Experimental Determination Of Colburn And Friction Factors In Small Plate Heat Exchangers With High Surface Enlargement Factors, Andrew H. Pike

Masters Theses

Experiments were conducted to measure the performance of several small brazed plate heat exchangers. A test apparatus was designed and constructed that allowed for the easy switching of the plate heat exchangers, as well as having the ability to electronically monitor and record the inlet and outlet temperatures, pressures, and flow rates. The flow rates and applied electrical power were controlled electronically by the same program which recorded the data. De-ionized water was used as the heat transfer medium to reduce the uncertainty related to fluid properties.

An existing mathematical model was used to create Colburn and friction factors based …