Mechanical Engineering Commons^™

The Influence Of Varying Fiber Stacking Sequence On The Tensile, Impact, And Water Absorption Properties Of Unidirectional Flax/E-Glass Fiber Reinforced Epoxy Composite, Mohammed F. Al-Edhari

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis includes the study of the mechanical performance of two different types of fibers reinforced hybrid composites. Two kinds of fibers, natural fiber (flax) and synthetic fiber (E-glass), are used to reinforce epoxy resin. To evaluate the effective properties of the hybrid composites, a micromechanical analysis of the structure genome (SG) of a unidirectional fiber hybrid composites is performed using nite element analysis (FEA). Both fibers are assumed to be circular and packed in a hexagonal pattern. The effects of varying volume fractions and fiber locations, of the two fibers, on the elastic properties of the hybrid composites are …

Shear Joy Of Watching Paint Dry, Randy Craig Hurd, Nathan B. Spiers, J. Belden, Zhao Pan, B. Lovett, W. G. Robinson, M. A. Zamora, Saberul I. Sharker, Mohammad M. Mansoor, A. Merritt, Tadd T. Truscott

Mechanical and Aerospace Engineering Faculty Publications

This paper is associated with a video winner of a 2016 APS/DFD Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion.

Visualization And 3d Printing Of A 3d Solar Tracker Model Using Mayavi And Pov-Ray, Aditya Mehra

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

In this work, we have created a realistic model of a solar tracker using Mayavi: 3D scientific data visualization and plotting in Python, Enthought Canopy:a comprehensive Python analysis environment and Persistence of Vision Ray Tracer, or POV-Ray, a ray tracing program which generates photo-realistic images from a text-based scene description, a model of the solar tracker was also 3D printed.

Heat Transfer Analysis Of Localized Heat-Treatment For Grade 91 Steel, Jacob D. Walker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many of the projects utilizing Grade 91 steel are large in scale, therefore it is necessary to assemble on site. The assembly of the major pieces often requires welding in the assembly; welding drastically changes the superior mechanical properties of Grade 91 steel that it was specifically developed for. Therefore, because of the adverse effects of welding on the mechanical properties of Grade 91, it is necessary to do a localized post weld heat treatment.

In this study a localized post weld heat treatment is used to gather experimental data. The data is then used to derive unknown heat transfer …

Phonon Dispersion And Relaxation Time In Uranium Dioxide, Dallin Parkinson

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

Phonon dispersion branches are used to obtain an effective relaxation time to calculate thermal conductivity of Uranium Dioxide (UO₂). The method presented closely follows that of Deskins’ phonon-phonon interaction that uses a three-phonon process which satisfies momentum and energy conservation. All phonon branches including longitudinal acoustic, transverse acoustic, longitudinal optical and transverse optical are considered in the calculation of the relaxation time.

After one phonon is identified, a scan is initiated to test all phonon combinations that will satisfy the conservation equations. When the scan identifies a valid three-phonon combination a relaxation time is calculated for that combination. …

Facilitation Of Nanoscale Thermal Transport By Hydrogen Bonds, Lin Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermal transport performance at the nanoscale and/or of biomaterials is essential to the success of many new technologies including nanoelectronics, biomedical devices, and various nanocomposites. Due to complicated microstructures and chemical bonding, thermal transport process in these materials has not been well understood yet. In terms of chemical bonding, it is well known that the strength of atomic bonding can significantly affect thermal transport across materials or across interfaces between materials. Given the intrinsic high strength of hydrogen bonds, this dissertation explores the role of hydrogen bonds in nanoscale thermal transport in various materials, and investigates novel material designs incorporating …

Analysis Of Angles-Only Hybrid Space-Based/Ground-Based Approach For Geosynchronous Orbit Catalog Maintenance, Blythe A. Andrews

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geosynchronous Equatorial Orbit (GEO) is critical to Earth communications, weather monitoring, and national defense. Orbit estimation of GEO objects is difficult due to physical constraints placed on ground-based tracking devices such as weather, object range, and tracking frequency restrictions. These constraints are commonly mitigated through the use of two-way signaling devices for cooperative GEO satellites. However, determining the position and velocity of uncooperative GEO satellites and/or objects is more challenging. The objective of this dissertation is to quantify the increased orbital accuracy of objects in the GEO catalog when the Air Force Space Command Space Surveillance Network (AFSPC SSN) is …

Three-Dimensional Printing Of "Green" Fuels For Low-Cost Small Spacecraft Propulsion Systems, Stephen A. Whitmore

Mechanical and Aerospace Engineering Faculty Publications

This paper details the advantages of employing modern additive manufacturing methods to fabricate hybrid rocket fuels for intrinsically safe and green small spacecraft propulsion systems. Using additive manufacturing overcomes multiple issues frequently associated with hybrid propulsion, including poor volumetric efficiency, system ignitability, and low fuel regression rates. When certain three-dimensionally printed thermoplastics are subjected to a high-voltage low-wattage charge, electrostatic arcing along the surface pyrolizes a small amount of material that, with the introduction of an oxidizer, “seeds” combustion and produces immediate and reliable ignition. Thermoplastic fuel grains can be printed with port shapes that enhance burn properties and increase …

Applications Of Relative Motion Models Using Curvilinear Coordinate Frames, Alex C. Perez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A new angles-only initial relative orbit determination (IROD) algorithm is derived using three line-of-sight observations. This algorithm accomplishes this by taking a Singular Value Decomposition of a 6x6 matrix to arrive at an approximate initial relative orbit determination solution. This involves the approximate solution of 6 polynomial equations in 6 unknowns. An iterative improvement algorithm is also derived that provides the exact solution, to numerical precision, of the 6 polynomial equations in 6 unknowns. The initial relative orbit algorithm is also expanded for more than three line-of-sight observations with an iterative improvement algorithm for more than three line-of-sight observations. The …

Design Baseline Document: Mini Baja Frame, Michael Luke Scoggins

Undergraduate Honors Capstone Projects

Our objective as the Mini Baja Frame team is to design and implement a prototype vehicle frame that is both cost-effective and competitive in an all-terrain racing environment. This vehicle must be able to endure the trials of the Society of Automotive Engineers (SAE) Mini Baja competition. An effective frame will contribute to the complete Utah State University Mini Baja Team objectives by efficiently integrating the components produced by the drivetrain and the suspension engineers. In addition, this competition is a means for us as students to gain valuable, tangible experience in the engineering design process.

Evaluation Of Flux Correction On Three-Dimensional Strand Grids With An Overset Cartesian Grid, Dalon G. Work

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Simulations of fluid flows over complex geometries are typically solved using a solution technique known as the overset meshing method. The geometry is meshed using grid types appropriate to the local geometry in a patchwork fashion, rather than meshing the entire geometry with one type of mesh. The strand-Cartesian approach is a simplification of this process. While high-order accurate solvers on Cartesian grids are simple to implement, strand grids are usually restricted to second-order accuracy, resulting in poor quality solutions. Flux correction is a high-order accurate solution method, specifically designed for use on strand grids. The flux correction method on …

Water Entry Impact Dynamics Of Diving Birds, Saberul Islam Sharker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plunge diving and surface diving are two main techniques used by seabirds for foraging purposes. While some plunge divers can dive into the water at very high speeds (24 m/s), surface divers do not. This study analyzes the free-surface impact of 3D printed bird head models with embedded accelerometers to determine why surface divers cannot dive safely at high speeds. The problem is investigated in the context of impact jerk where surface divers, unlike plunge divers, are found to experience non-dimensional jerk (J^∗) values exceeding a safe limit. This approach portrays itself as an unconventional yet effective method …

Characterization Of The Thermal Resistance Of Grain Boundaries Of Cerium Oxide, Jesse Spackman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many materials are made up of small crystals, or grains. Grain boundaries are the interfaces between two grains and affect the flow of heat through the material. These interfaces serve to interfere with the energy carriers by scattering or disrupting them. Because of the negative effect these interfaces have on these energy carriers, they inhibit heat flow and act as thermal resistors. The thermal boundary resistance between two grains of the same material is sometimes referred to as the Kapitza resistance, although this term is also used to describe the thermal resistance between solid/solid interfaces of different materials or solid/liquid …

Effects Of Computer Simulation And Animation (Csa) On Students’ Problem Solving In Engineering Dynamics: What And How, Seyed Mohammad Tajvidi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous studies have shown that in many fields, computer simulation and animation (CSA) improve students’ learning and problem solving. However, despite the massive body of research on the role of computers in education, little research has been conducted to qualitatively examine how they affect the learning of engineering students. The purpose of this study was to explore how learning and problem solving were affected by computer modules and what similarities and differences existed between computer representations and paper-based examples.

An analysis of collected data, observations of participants’ problem-solving activities, and interviews revealed that computers can enhance students’ analytical thinking, organizing, …

Role Of Dispersion And Functionalization On Mechanical Properties In Carbon Nanotube - Polymer Composite, Medisetti Sai Praveen Kumar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polymer composites with carbon nanotubes (CNT) as filler material is an exciting research area, having a huge potential of offering better mechanical properties. One of the main challenges of using CNT as a filler material is mixing of CNTs within the matrix material, as this mixing determines the strength of the composite. Some of the methods being researched for improving mixing are chemical, mechanical and surfactants. Many studies have suggested high frequency mechanical stirring as the preferred way for better mixing, but challenges exist with finding the proper solvent which can be used for stirring and at the same time …

Nonlinear Photothermal Radiometry And Its Applications To Pyrometry And Thermal Property Measurements, Austin Drew Fleming

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Accurate temperature and thermal property measurements are critical for the modeling and prediction of heat transfer. In many industries thermal management is a limiting factor of performance, and rely on advanced modeling techniques to develop and design methods to better manage thermal energy. This study expands the thermal property and pyrometry measurement capabilities by developing three new techniques based on thermal emission’s nonlinear dependence on temperature.

Mechanical Performance Of Natural / Natural Fiber Reinforced Hybrid Composite Materials Using Finite Element Method Based Micromechanics And Experiments, Muhammad Ziaur Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A micromechanical analysis of the representative volume element (RVE) of a unidirectional flax/jute fiber reinforced epoxy composite is performed using finite element analysis (FEA). To do so, first effective mechanical properties of flax fiber and jute fiber are evaluated numerically and then used in evaluating the effective properties of flax/jute/epoxy hybrid composite. Mechanics of Structure Genome (MSG), a new homogenization tool developed in Purdue University, is used to calculate the homogenized effective properties. Numerical results are compared with analytical solution based on rule of mixture, Halpin-Tsai as well as Tsai-Hahn equations. The effect of the volume fraction of the two …

Investigating The Highest Melting Temperature Materials: A Laser Melting Study Of The Tac-Hfc System, Omar Cedillos-Barraza, Dario Manara, K. Boboridis, Tyson Watkins, Salvatore Grasso, Daniel D. Jayaseelan, Rudy J. M. Konings, Michael J. Reece, William E. Lee

Mechanical and Aerospace Engineering Student Publications and Presentations

TaC, HfC and their solid solutions are promising candidate materials for thermal protection structures in hypersonic vehicles because of their very high melting temperatures (>4000 K) among other properties.  The melting temperatures of slightly hypostoichiometric TaC, HfC and three solid solution compositions (Ta1−xHfxC, with x = 0.8, 0.5 and 0.2) have long been identified as the highest known. In the current  research, they were reassessed, for the first time in the last fifty years, using a laser heating technique.  They were found to melt in the range of 4041–4232 K, with HfC having the highest and TaC the lowest. …

Design For Manufacturability And Assembly Of An Assistive Technician Creeper, Including Single Drive Control Of A Multi-Degree Of Freedom Kinematic Mechanism, Larry T. Wilde Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2011, a team of engineering students at Utah State University designed and built an assistive technician creeper to assist persons with lower-extremity physical disabilities to work in low-clearance areas. In order to put this technology on the market, a complete product redesign was needed to address safety and functionality concerns. This thesis outlines the specific design needs, presents the detailed design approach, and summarizes the final creeper solution. The mechanisms of the initial prototype were modified to independently incline or recline the upper body, and raise or lower the seat surface with a single motor. This will be especially …

Best Practices For Volume Flow Rate Measurements Using Piv At The Exit Of A Turbulent Planar Jet, Rick Cressall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particle image velocimetry (PIV) is used to make volume-flow-rate measurements at the exit of a turbulent, planar nozzle. The objective of this report is to assess a range of data acquisition and processing parameters. Data is acquired for volume flow rates of Reynolds numbers between 10,000 and 100,000 for both two-component (2C) and stereo PIV. The parameters are systematically changed one at a time and evaluated using differences in uncertainty, calculation time, and volume- flow-rate deviation. Data acquisition parameters follow the trends of previous work. A multitude of processing parameters were varied for several PIV processing methods. Recommendations for each …

Survey Of Selected Additively Manufactured Propellant For Arc-Ignition Of Hybrid Rockets, Stephen A. Whitmore, Stephen L. Merkley, Louis Tonc, Spencer D. Mathias

Mechanical and Aerospace Engineering Faculty Publications

Results of a testing campaign to assess multiple commercially available three-dimensional printer materials for effectiveness in an arc-ignition system for hybrid rockets are presented. Previously, a form of additive manufacturing known as fused deposition modeling was used to fabricate high-density acrylonitrile butadiene styrene (ABS) fuel grains so that, when properly layered, they possess unique electrical breakdown properties. When subjected to an inductive charge, an electrical arc flows along the layered material surface and seeds combustion when the arc occurs simultaneously with the introduction of an oxidizing flow. This study investigates commercially available three-dimensional printable materials to search for equivalent or …

Enhanced Thermal Conductance Of Polymer Composites Through Embedding Aligned Carbon Nanofibers, David S. Wood, Dale K. Hensley, Nicholas A. Roberts

Mechanical and Aerospace Engineering Faculty Publications

The focus of this work is to find a more efficient method of enhancing the thermal conduc-tance of polymer thin films. This work compares polymer thin films embedded with randomly oriented carbon nanotubes to those with vertically aligned carbon nanofibers. Thin films embedded with carbon nanofibers demonstrated a similar thermal conductance between 40–60 µm and a higher thermal con-ductance between 25–40 µm than films embedded with carbon nanotubes with similar volume fractions even though carbon nanotubes have a higher thermal conductivity than carbon nanofibers.

Techno-Economic Assessment Of Micro-Algae Production Systems, Justin Hoffman

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

Global oil consumption is rising at an unprecedented rate renewing interest in alternative fuels. Micro-algae represents a promising feedstock due to inherent advantages such as high solar energy efficiencies, large lipid fractions, and utilization of various waste streams including industrial flue gas. Current technological challenges have limited the commercial viability of microalgae based biofuel production systems. This study directly evaluates and compares the economic viability of biomass production from two different open cultivation platforms, 1) algal turf scrubbers and 2) open raceway ponds. Modular sub-process models were developed and leveraged for the economic comparison of the systems on the metrics …

Investigating The Effect Of Carbon Nanotube Functionalization In A Polydimethylsiloxane Composite Through Use Of A Stepped Bar Apparatus, Matthew I. Ralphs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermal interface materials (TIMs) are used in transporting heat away from a circuit or electronic module. Composite materials are a popular research area for TIMs because they allow the desired properties to be joined in a composite to take advantage of the best properties from all the constituents involved. The composite selected for this study uses carbon nanotubes (CNT) as the filler and an elastomeric polymer for the matrix, specifically a multiwalled carbon nanotube (MWCNT) / polydimethylsiloxane (PDMS) composite. This study looks at chemical modification (functionalization) of the CNTin an effort to produce a better bond between the CNT and …

Xhab Microgravity Food Growth Chamber, Nathan I. Stacey

Undergraduate Honors Capstone Projects

NASA and other organizations are preparing to send humans deeper into space, including a NASA manned mission to Mars in the 2030s, in order to learn more about our universe and the origin of life and to ensure the survival of the human race. Long journeys in space require efficient, dependable, and sustainable methods to provide for astronauts' metabolic needs such as oxygen, water, and food. In order for microgravity plant growth chambers to become a viable solution, several challenges encountered by past growth chambers must be resolved.

One problem with existing space food growth chambers is hypoxia, or lack …

Pedicle Lengthening Spacer, David S. Wood

Undergraduate Honors Capstone Projects

In the lumbar region of the spine, the spinal cord travels through a small hole in your vertebrae called the spinal canal. There is a medical condition where the spinal canal becomes restricted. This condition is called stenosis. There are several reasons for this pinching of the spinal column. These include the growth of bone spurs, the accumulation of ligaments in the canal, or a genetic trait. When these occur in the lower five vertebrae (the lumbar region), it is called lumbar stenosis. The symptoms of Lumbar Stenosis are shooting pain through the legs, especially during activity, and feelings of …

Modified Trajectory Shaping Guidance For Autonomous Path Following Control Of Platooning Ground Vehicles, Ishmaal T. Erekson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis proposes a modification of trajectory shaping guidance to provide more accurate path convergence in curved paths. The object of this thesis is to apply this simple guidance law to platooning control to ensure all vehicles in the platoon converge to a desired constant radius path at a desired vehicle separation distance. To show the viability of this new guidance law, it is shown mathematically to be exponentially stable. It is also confirmed through simulations and on ground robots.

Understanding Pyrotechnic Shock Dynamics And Response Attenuation Over Distance, Richard J. Ott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Component requirements govern design and production in the aerospace industry. One such potential requirement for a component is the survival and continued function upon exposure to shock environments. A shock event is a high amplitude, short duration traveling wave that induces large loads on components in its path that can cause degradation of electronic components, cracks and fractures in brittle materials, local plastic deformation, and materials to experience accelerated fatigue life. In defining these environments for new structures, industry experts rely mainly on empirical data. Measurements from similar structures are scaled and enveloped to create a predicted bounding case. This …

Investigating The Effect Of Capping Layers On Final Thin Film Morphology After A Dewetting Process, Benjamin C. White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nanoparticles on a substrate have numerous applications in nanotechnology, from enhancements to solar cell efficiency to improvements in carbon nanotube growth. Producing nanoparticles in a cheap fashion with some control over size and spacing is difficult to do, but desired. This work presents a novel method for altering the size and spacing of nickel and gold nanoparticles. Dewetting is a methodology to reduce thin films to an ensemble of discrete droplets. The introduction of alumina capping layers to thin nickel films during a pulsed laser-induced dewetting process has yielded reductions in the mean and standard deviation of radii and pitch …

Path Following By A Quadrotor Using Virtual Target Pursuit Guidance, Abhishek Manjunath

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Missile guidance laws have been solely developed to follow and intercept a target thereby destroying or damaging it. In this research, the primary objective is to modify and adopt a missile guidance law to be used on a quadrotor to follow a virtual target. The target is termed 'virtual' as it only exists mathematically in the form of equations. The goal is to have the quadrotor successfully following the predefined path (described by the target) while maintaining a fixed distance from the virtual target. To ensure viability and assess performance, a detailed comparison with another path following law is made.