Mechanical Engineering Commons^™

Dynamics And Control Of Wrist And Forearm Movements, Allan W. Peaden

Theses and Dissertations

Wrist and forearm motion is governed both by its dynamics and the control strategies employed by the neuromuscular system to execute goal oriented movement. Two experiments were conducted to increase our understanding of wrist and forearm motion. The first experiment involved 10 healthy subjects executing planned movements to targets involving all three degrees of freedom (DOF) of the wrist and forearm, namely wrist flexion-extension (FE), wrist radial-ulnar deviation, and forearm pronation-supination (PS). A model of wrist and forearm dynamics was developed, and the recorded movements were fed into the model to analyze the movement torques. This resulted in the following …

A Study Of Action Origami As Systems Of Spherical Mechanisms, Landen A. Bowen

Theses and Dissertations

Origami, the Japanese art of paper folding, has been used previously to inspire engineering solutions for compact, deployable designs. Action origami, the subset of origami dealing with models designed to move, is a previously unexplored area for engineering design solutions that are deployable and have additional motion in the deployed state. A literature review of origami in engineering is performed, resulting in seven key areas of technical origami literature from a wide variety of disciplines. Spherical mechanisms are identified as the method by which most action origami models achieve complicated motion while remaining flat-foldable. The subset of action origami whose …

Capillary Filling Of Large Aspect Ratio Channels With Varying Wall Spacing, Dallin B. Murray

Theses and Dissertations

Quantification and prediction of capillary fluid flow in planar nanochannels is essential to the development of many emerging nanofluidic technologies. Planar nanochannels are typically produced using the standard nanofabrication processes of thermal bonding or sacrificial etching. Both approaches may yield nanochannels that are bowed and/or exhibit non-uniform (i.e. non-planar) wall spacing. These variations in wall spacing affect the transient dynamics of a liquid plug filling the nanochannel, causing deviations from the classical behavior in a parallel-plate channel as described by the Washburn model. Non uniform wall spacing impacts the overall frictional resistance and influences the meniscus curvature. In this thesis, …

Untitled, Evan Beyers, Jonathan Ogland-Hand

Symposium on Research and Creative Expression (SORCE)

The solar furnace research project at Valparaiso University utilizes a decoupled solar thermal electrolysis process for the production of H2 from water. We are focusing on an iron oxide system, which involves the conversion of magnetite to hematite in a cyclical process. Our experimental study for the iron oxide system confirmed that the electrolytic oxidation and thermal reduction steps of the metal oxide occur in a laboratory scale environment. Unfortunately, some of the Fe+3 products for the magnetite system stays in solution when the electrolysis is done in a strong acid. We needed to develop methods to quantify the fraction …

The First Step In Solar Hydrogen Production: Development Of A Solar Thermal Reactor For The Reduction Of Metal Oxide Particles, Jesse Fosheim, Andrew Schrader

Symposium on Research and Creative Expression (SORCE)

A solar thermal reactor has been designed to experimentally investigate promising paths for reducing metal oxide particles to reduced oxidation states (e.g. Fe2O3 to Fe3O4) utilizing concentrated solar energy. This reactor is windowless and is able to handle internal cavity temperatures in excess of 1700 K. It also has a quasi-continuous feed system that allows the particle residence times to be varied for particles between 0.044 mm and 1 mm in diameter. Furthermore, this reactor utilizes an instrumentation system for the measurement of temperature, particle residence time, particle mass flow rate, and solar flux. In an industrial setting, a large-scale …

Environmental And Economically Conscious Magnesium Production: Solar Thermal Electrolytic Production Of Mg From Mgo, J Fosheim, C Baum, B Borth, B Gruenwald, P Nasserifar, G Vanheeren, R Palumbo, E Beyers, R Diver, S Duncan, P Kissinger, S Nudehi, J Ogland-Hand, L Saks, J Schoer, A Schrader, L Venstom

Symposium on Research and Creative Expression (SORCE)

One method to improve the fuel efficiency of American made vehicles is to reduce vehicle weight by substituting steel components with lighter magnesium (Mg) components. Unfortunately, U.S. produced Mg currently costs approximately $3.31 per kg, over seven times the price of steel. Furthermore, Mg production has a staggering energy and environmental impact, consuming up to 102 kW-hr/kg-Mg of energy and producing 36 kg of CO2/kg-Mg. To reduce the overwhelming economic and environmental impact of Mg, a new solar thermal electrolytic process has been developed for the production of Mg from MgO. Through this process, liquid Mg is produced in a …

Preliminary Development Of A Subject Specific Finite Element Model Of The Hindfoot, Liang Dong

Mechanical & Aerospace Engineering Theses & Dissertations

The human hindfoot is a complex structure and its medical treatment can vary from patient to patient. If physicians have access to a patient specific computer model, the optimal treatment option can be explored on the model before preforming it on the patient. The purpose of this study was to create a quasi-static finite element model and to show the stress contour in the cartilage between the bones. Ankle joint contact pressure was collected on one cadaver limb with a 40 lbs ( 178 N) axial load applied and tendon loads applied to simulate the ratio of tendon loading during …

Development And Assessment Of An In-Situ Load System, Kenneth Toro

Mechanical & Aerospace Engineering Theses & Dissertations

The In-situ Load System (ILS) was designed at NASA Langley Research Center (LaRC) to perform multi-component check loads on a force balance at a test facility. The ILS is designed to allow a force balance to be placed at off nominal orientations, while maintaining an applied load in the gravitational direction. This allows for multicomponent loads to be applied to a balance as a function of balance orientation and ILS configuration. The system is designed to be used in conjunction with a facilities existing pitch and roll control systems.

The ILS was modified to provide higher load ranges than those …

Multi-Objective Preliminary Design Optimization Of Planing Craft Using Differential Evolution And Artificial Networks, Robert Eugene Weidman

Mechanical & Aerospace Engineering Theses & Dissertations

The differential evolution (DE) algorithm is an evolutionary algorithm that has been utilized as a metaheuristic optimizer in the last few years. A recently developed multi-objective version of DE is utilized in this research in order to optimize the preliminary design of planing craft. The craft performance is evaluated using the planing hull preliminary design software PHAST. The optimization problem objectives are the craft acquisition cost and the overall measure of effectiveness; the latter comprises various performance aspects: ride quality, transportability, payload, and mobility. Static stability and operating constraints are also considered. Each of the aforementioned four measures of effectiveness …

Dynamic Modeling Of A Belt Driven Electromechanical Xy Plotter Cutter, Joseph V. Prisco

Master's Theses (2009 -)

Current industrial XY plotter cutters that use a belt driven gantry for the X motion and media feed for the Y motion sometimes have performance issues in cutting out high quality shapes. Mathematical models for these plotter cutters are not publicly available and thus the parameters critical to cut quality are not well understood. This thesis develops a dynamic, electromechanical model for the gantry arm and media feed using first principles and a non-linear friction model. These models are independently simulated and experimentally verified. In order to verify the effectiveness of the individual models, they are combined with a control …

Static And Vibration Analyses, And Sensitivity Analysis Of Stepped Beams Using Singularity Functions, Carla Rocio Davila

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis intends to prove that singularity functions can be used to perform static and vibration analyses and their sensitivity analysis of stepped beams subjected to various support constraints. Specifically, this thesis develops formulations using singularity functions for static and vibration analyses of a simply-supported, a roller­ supported, and a spring-supported stepped beam. The Static and Vibration Sensitivity Analysis formulations are derived for the simply-supported beam to show the feasibility of this approach. The techniques presented in this thesis can be extended to various other supports constraints such as a middle support, and spring support or any other variation of …

Microphone-Based Pressure Diagnostics For Boundary Layer Transition, Spencer Everett Lillywhite

Master's Theses

An experimental investigation of the use low-cost microphones for unsteady total pressure measurement to detect transition from laminar to turbulent boundary layer flow has been conducted. Two small electret condenser microphones, the Knowles FG-23629 and the FG-23742, were used to measure the pressure fluctuations and considered for possible integration with an autonomous boundary layer measurement system. Procedures to determine the microphones’ maximum sound pressure levels and frequency response using an acoustic source provided by a speaker and a reference microphone. These studies showed that both microphones possess a very flat frequency response and that the max SPL of the FG-23629 …

Heating Effects Through Harmonic Distortion On Electric Cables In The Built Environment, Kevin O'Connell

Doctoral

Under ideal circumstances, electric power supply voltage and current waveforms should be sinusoidal. However, this is very seldom the case in the built environment, due to the proliferation of non-linear loads. Examples of non-linear loads are those containing switched mode power supplies, reactors and electronic rectifiers/inverters. Common devices such as personal computers, fluorescent lighting, electric motors, variable speed drives, transformers and reactors and virtually all other electronic equipment are examples of non-linear loads. Non-linear loads are the norm in the built environment rather than the exception. Such loads produce complex current and voltage waves and simple spectral analysis of these …

Field Emission Studies Toward Improving The Performance Of Dc High Voltage Photoelectron Guns, Mahzad Bastaninejad

Mechanical & Aerospace Engineering Theses & Dissertations

Field emission is the main mechanism that prevents DC high voltage photoemission electron guns from operating at the very high bias voltages required to produce low emittance beams. Gas conditioning is shown to eliminate field emission from cathode electrodes used inside DC high voltage photoelectron guns. Measurements and simulation results indicate that gas conditioning eliminates field emission from cathode electrodes via two mechanisms: sputtering and implantation, with the benefits of implantation reversed by heating the electrode. The field emission characteristics of 5 stainless steel electrodes varied significantly upon the initial application of voltage but improved to nearly the same level …

Subtalar Joint Instability: Diagnosis And Conservative Treatment, Julie Choisne

Mechanical & Aerospace Engineering Theses & Dissertations

Subtalar instability may be caused by various ligamentous injuries. Combined instability at the ankle and subtalar joint is not adequately diagnosed. Further, isolated subtalar instability is usually misdiagnosed which may lead to long term damage to the joint. Developing a non-invasive and clinically practical tool to diagnose subtalar joint instability would be an important asset. The ability of an ankle brace, a common treatment for hindfoot instability, to promote stability for the subtalar joint was not well established. The purposes of this study were to 1) assess the kinematics of the subtalar, ankle, and hindfoot in the presence of isolated …

Numerical Simulation Of Convection In Triangular Cavities To Predict Solar Still Performance, Jeremy D. Lefevre, W. Jerry Bowman, Matthew R. Jones

Faculty Publications

To improve modeling of solar still behavior, the convection correlations currently used need to be improved upon. Variations in operating parameters and cover geometries make it difficult to use a single correlation to describe the operation of all solar stills. In this work, three right triangles (representing covers at 15, 30, and 45 deg) were modeled, meshed, and solved to predict the convection heat transfer inside for a variety of operating conditions. For a correlation of the form Nu = C · Raⁿ, it was found that C = 1.1, 0.60, and 0.71, and n = 0.19, 0.24, …

A Multi-Scale Approach To A Greater Understanding Of The Behavior Of Heterogeneous Materials Under Dynamic Loading, Andrew J. Van Vooren

Master's Theses (2009 -)

The penetration of granular materials is of interest to a variety of different fields, and is an active area of research. The objective of this project is to gain understanding of the dynamics of a projectile penetrating into a granular material. To do this, experiments were run and a numerical model was created.

A dart gun was used to accelerate an aluminum dart to velocities around 100 m/s, which then impacted a target tank filled with Ottawa sand. The dart flew along a view window, which allowed for a recording of the penetration event using a high speed camera. Pressure …

Flame Temperature Imaging Of A Low Nox Burner Via Laser Rayleigh Scattering, Nicholas A. Smith

Master's Theses (2009 -)

Federal and global legislation are requiring increasingly stringent emission regulation on household appliances and in particular water heater burners. Emissions like NOx (NO and NO2) are a growing concern due to their adverse health effects and contribution to tropospheric ozone, acid rain, and smog formation. As NOx is more closely controlled, appliance manufacturers are developing low emission burners for use in water heaters.

Flame temperature is strongly correlated to NOx production. Hence, characterizing flame temperatures in new burners is a key part of improving upon burners used today and the development of future burners. Temperature measurements applied to a new, …

Near- And Far-Field Spectroscopic Imaging Investigation Of Resonant Square-Loop Infrared Metasurfaces, J. D'Achangel, E. Tucker, Edward C. Kinzel, E. A. Muller, H. A. Bechtel, M. B. Martin, G. Boreman

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Inviscid Analysis Of Extended Formation Flight, James Kless, Michael Aftosmis, Andrew Ning, Marian Nemec

Faculty Publications

Flying airplanes in extended formations, with separation distances of tens of wingspans, significantly improves safety while maintaining most of the fuel savings achieved in close formations. The present study investigates the impact of roll trim and compressibility at a fixed lift coefficient on the benefits of extended formation flight. An Euler solver with adjoint-based mesh refinement combined with a wake propagation model is used to analyze a two-body echelon formation at a separation distance of 30 spans. Two geometries are examined: a simple wing and a wing-body geometry. Energy savings, quantified by both formation drag fraction and span efficiency factor, …

The Effect Of Microencapsulated Phase-Change Material On The Compressive Strength Of Structural Concrete, Chad Norvell, David J. Sailor, Peter Dusicka

Mechanical and Materials Engineering Faculty Publications and Presentations

Latent heat energy storage through phase-change materials (PCMs) is one possible strategy to control interior temperatures in buildings, improve thermal comfort, and passively reduce building energy use associated with heating and cooling. While PCMs integrated into building structure elements have been studied since the 1970s, challenges of integrating PCMs into building materials while maintaining their heat storage benefits have limited their application in practice. The recent introduction of microencapsulated phase-change materials provides the energy storage capability of PCMs in micron-scale, chemically-inert capsules that can be easily integrated into composite materials such as gypsum wallboard and concrete. The size and physical …

Improvement Of Hydraulic Press For Vegetable Oil Expression In Rural Areas, I. P. Bateebe

Tanzania Journal of Engineering and Technology (TJET)

Cultivation of oil producing crops especially Jatropha and croton as source of vegetable oil for biodiesel production is being encouraged in rural areas. To recover oil from seed, manual press is the feasible method in rural areas where there is no electricity. Research was conducted to improve hydraulic oil press machine for rural application. Factors affecting oil recovery were found to be: moisture content of seeds, operating pressure, seed oil content, and the amount of seeds pressed per batch. Percentage oil recovery was improved by reducing diameter of press cylinder, hence increasing expression pressure, and either reducing amount of seed …

Investigation Of Thermal Properties And Latent Heat Reduction Mechanisms In Nanofluid Phase Change Materials, Aitor Zabalegui

Mechanical Engineering Master's Theses

The thermal properties of paraffin-based nanofluids have been examined to investigate the use of enhanced phase change materials (PCMs) for thermal energy storage (TES). PCMs are promising for TES applications, but low thermal conductivity limits their rate of heat exchange with a working fluid. The nanofluid approach has been established as a method of thermal conductivity enhancement, but effects of particle addition on other thermal properties affecting TES are relatively ignored. Significant reduction in latent heat of fusion below traditional effective medium theory has been observed in nanofluids. An experimental study of paraffin nanofluids, containing various diameter multi-walled carbon nanotubes, …

Boiling Heat Transfer On Superhydrophobic Surfaces, Nathan Tulett, Dr. Daniel Maynes

Journal of Undergraduate Research

In the last few years a great deal of attention has been given to superhydrophobic surfaces and their impact on drag reduction in fluid flow dynamics. Such surfaces are now employed as self-cleaning substrates and it is expected that their use in the coming years will greatly multiply. In the laboratory, these surfaces often consist of alternating microribs and microcavities that are etched into a silicone substrate using a deep reactive ion etching process (DRIE) as seen in Fig. 1.

Optimizing Redundant Wrist And Forearm Rotations, Jenny Pate, Dr. Steven Charles

Journal of Undergraduate Research

Many Americans struggle with wrist injuries that severely impact their ability to work (typing, writing, etc.) and perform basic everyday functions (eating, holding, etc). These injuries often result from repeatedly forcing the wrist to move in unnatural ways. To properly combat these challenges and improve the lives of wrist patients, a better understanding of the human wrist is required. Extensive research has been conducted in arm reaching movements, but limited documentation has been presented regarding the human wrist. In particular, although it appears that humans choose certain wrist movements over others, it is unclear which paths are preferred, why they …

Apparatus And Method For Growing Biological Organisms For Fuel And Other Purposes, David J. Bayless, Morgan Lefay Vis-Chiasson, Ben J. Stuart, Gregory G. Kremer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A bioreactor apparatus in which a container has sidewalls, a floor and a ceiling defining a chamber that contains a slurry of water, nutrients and photosynthetic microorganisms. A plurality of optical fibers, each of which has a first end disposed outside the chamber and a second end in the mixture. A light collector spaced from the container has light incident on it and focuses the light onto the first ends of the plurality of optical fibers, thereby permitting the light to be conveyed into the mixture to promote photosynthesis. At least one nozzle is in fluid communication with a source …

Using Ebsd Images To Determine 3d Crystal Structure, Caroline Sorensen, Dr. David Fullwood

Journal of Undergraduate Research

The research I have completed over the past year has been very successful. The results will soon (i.e. in the next week or two) be submitted for publication, most likely to the journal “Metallurgical and Material Transactions A.” Preliminary findings from this research were also presented earlier this year at the annual conference of The Minerals, Metals, & Materials Society in San Diego, CA. In this final report I will overview the initial goal and proposed methods, outline a few of the problems that were encountered and solved in my research, discuss the implications of the results, and suggest further …

High Resolution Characterization Of Polycrystalline Triple Junctions, Samikshya Subedi, Dr. David Fullwood

Journal of Undergraduate Research

The purpose of this study was to understand and predict the role of the triple junction on crack initiation in polycrystals. I intended to study dislocation density fields and local elastic strain around the triple junction area in a metal and understand how these factors facilitate crack nucleation and propagation.

Flapping Flight, Michael Tree, Dr. Scott Thomson

Journal of Undergraduate Research

Operation of existing micro air vehicles (small, unmanned aircraft, with a maximum size of 6 inches or less, also known as MAVs) is difficult in urban areas. Most MAVs use a fixed-wing design that is unsuitable for high maneuverability, thus limiting their potential usefulness.

Mathematical Dynamics Of Fluid Motion Inside Of A Spherical Boundary, Taylor Killian, Dr. Tadd Truscott

Journal of Undergraduate Research

The purpose of the proposed research was to mathematically define and model the flow of fluid within a partially filled sphere. The goal of this modeling was to aid the study of the effects an enclosed fluid had on its boundary. We desired to demonstrate the movements of the fluid numerically. Professor Truscott’s laboratory observed that the rebound of a sphere, partially filled with fluid, is greatly reduced by the motion of the fluid inside the sphere and wanted to understand the dynamics of this event.