Mechanical Engineering Commons^™

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. …

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 …

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 …

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.

Development Of A Three-Dimensional High-Order Strand-Grids Approach, Oisin Tong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The strand-Cartesian grid approach is a unique method of generating and computing fluid dynamic simulations. The strand-Cartesian approach provides highly desirable qualities of fully-automatic grid generation and high accuracy. This work focuses on development of a high-accuracy methodology (high-order scheme) on strand grids for two and three dimensions.

In this work, the high-order scheme is extended to high-Reynolds number computations in both two and three dimensions with the Spalart-Allmaras turbulence model and the Menter SST turbulence model. In addition, a simple limiter is explored to allow the high-order scheme to accurately predict discontinuous flows.

Extensive verification and validation is conducted …

Throttleable Gox/Abs Launch Assist Hybrid Rocket Motor For Small Scale Air Launch Platform, Zachary S. Spurrier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability for an aircraft-based launch platform to place an orbital payload onto a nominal launch trajectory at a higher energy state -- altitude, velocity, flight path angle, and azimuth --using highly-efficient air breathing propulsion instead of a much lower-efficiency rocket system, offers the potential for a significantly smaller launch vehicle. An airborne platform also provides the ability to launch from multiple locations and allows for significantly increased "system responsiveness." The NASA Armstrong Flight Research Center’s Towed Glider Air-Launch System (TGALS) is a small-scale flight research project investigating the feasibility for a remotely-piloted, towed, glider system to act as a …

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.

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 …

Thermal Property Measurement Of Thin Fibers By Complementary Methods, Troy Robert Munro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thin fibers are prevalent in many engineering materials. Measuring how well heat transfers in such small fibers can be difficult to determine, and previous methods have led to erroneous results. This dissertation details three proposed methods to improve the measurement of the thermal conductivity, thermal diffusivity, and volumetric heat capacity of thin fibers. Of particular interest is natural and synthetic spider silks because previously published values of the natural silk thermal conductivity was similar to copper, an excellent thermal conductor.

The three methods developed are the improved transient electrothermal technique (which was redeveloped to include radiation and convection heat losses …

Low-Temperature Aqueous Corrosion Behavior Of Uranium Molybdenum Alloys, Levi D. Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nuclear fuel characterization requires understanding of the various conditions to which materials are exposed in-reactor. One of these important conditions is corrosion, particularly that of fuel constituents. Therefore, corrosion behavior is of special interest and an essential part of nuclear materials characterization efforts. In support of the Office of Material Management and Minimization’s Reactor Conversion Program, monolithic uranium-10 wt% molybdenum alloy (UMo) is being investigated as a low enriched uranium alternative to highly enriched uranium dispersion fuel currently used in domestic high performance research reactors. The aqueous corrosion behavior of U-Mo is being examined at Pacific Northwest National Laboratory (PNNL) …

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 …

Rudder Augmented Trajectory Correction For Unmanned Aerial Vehicles To Decrease Lateral Image Errors Of Fixed Camera Payloads, Thomas M. Fisher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When using small unmanned aerial vehicles (UAVs) with cameras onboard for ground surveying, two competing problems arise. First is the desire to keep the camera sensor parallel with the ground and second is to maintain the proper flight path. When the cameras are physically fixed to the UAV and as the plane banks to maintain the desired path, the camera sensor is no longer kept parallel with the ground. This thesis focuses on a method called rudder augmented trajectory correction that allows for flat turns instead of banking the aircraft. Because of this, the camera is able to stay parallel …

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 …

Synthetic Spider Silk Sustainability Verification By Techno-Economic And Life Cycle Analysis, Alan Edlund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Major ampullate spider silk represents a promising biomaterial with diverse commercial potential ranging from textiles to medical devices due to the excellent physical and thermal properties from the protein structure. Recent advancements in synthetic biology have facilitated the development of recombinant spider silk proteins from Escherichia coli (E. coli), alfalfa, and goats. This study specifically investigates the economic feasibility and environmental impact of synthetic spider silk manufacturing. Pilot scale data was used to validate an engineering process model that includes all of the required sub-processing steps for synthetic fiber manufacture: production, harvesting, purification, drying, and spinning. Modeling was constructed modularly …

Computational Fluid Dynamic Modeling Of Natural Convection In Vertically Heated Rods, Mahesh Surendran

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural convection is a phenomenon that occurs in a wide range of applications such as cooling towers, air conditioners, and power plants. Natural convection may be used in decay heat removal systems such as spent fuel casks, where the higher reliability inherent of natural convection is more desirable than forced convection. Passive systems, such as natural convection, may provide better safety, and hence have received much attention recently. Cooling of spent fuel rods is conventionally done using water as the coolant. However, it involves contaminating the water with radiation from the fuel rods. Contamination becomes dangerous and difficult for humans …

Quadrotor Uav Path Following Using Trajectory Shaping, Parwinder Singh Mehrok

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The propose of this research is to develop a path following control law known as Trajectory Shaping. The approach is to develop a three- dimensional (3D) version of it from an existing two-dimensional (2D) model. Apart from research on this 3D control law, a multirotor unmanned aerial vehicle (UAV) platform, having four rotors and known as quadrotor is designed from the ground up for validating the concept of path following. Several pre-defined paths like the circle and figure-eight trajectories are used to apply the newly developed version of this control law. The existing 2D concept of Trajectory Shaping guidance …

Impact Of Heavy Metal Contamination From Coal Flue Gas On Microalgae Biofuel And Biogas Production Through Multiple Conversion Pathways, Derek E. Hess

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microalgae has a great potential to help alleviate the world's current dependence on fossil fuels. Microalgae is a single celled organism that produces lipids as a food storage device much like humans and animals store fat. These lipids are a kind of oil that when harvested can be utilized as biofuel.

As the technology surrounding using microalgae as a source of biofuel has advanced key bottlenecks in the eventual large-scale production of microalgae based biofuel have been discovered. One of these bottlenecks is the need to cheaply supply carbon for microalgae growth. One idea that has emerged as a plausible …

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 …

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.

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 …

Gas Gap Conductance Between Ht9 And Ss316, Michael Luke Scoggins, Chris Martinez

Student Research Symposium

Inside a nuclear reactor, it is important to understand in detail the heat transfer between surfaces. This research aims to ensure the safety of new fuel experiments in the Idaho National Laboratory test reactor by studying the thermal properties of stainless steel and high temperature steel surfaces with a microscopic gas gap between them. The complex behavior of the gas requires a combination of experimental and theoretical modeling. A technique called laser flash analysis is being applied to calculate the effective thermal conductivity of the metal-gas-metal composite sample. From there, gap conductance is calculated using the other known physical parameters …