Mechanical Engineering Commons^™

Safer Sweep Auger Operation Using Robotics, Nathan A. Wulf

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis presents a remotely controlled robotic solution for those who must sometimes enter agriculturally confined spaces in attempts to assist with grain bin cleanout, particularly by manipulating the sweep auger. In 2015 alone, there were at least 47 documented incidents that occurred in agriculturally confined spaces, of which more than half were fatal. While there have been several advancements in the quality and effectiveness of sweep augers, there have been very few that offer the safety and adaptability of the robotic solution proposed. This robotic solution is a four-wheeled, skid-steering style robot with camera and lighting attachments that allow …

Peridynamic Models For Fatigue And Fracture In Isotropic And In Polycrystalline Materials, Guanfeng Zhang

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

To improve design and reliability, extensive efforts has been devoted to understanding damage and failure of materials and structures using numerical simulation, as a complement of theory and experiment. In this thesis, peridynamics is adopted to study fatigue and dynamic failure problems.

Fatigue is a major failure mode in engineering structures. Predicting fracture/failure under cyclic loading is a challenging problem. Classical model cannot directly be applied to problems with discontinuities. A peridynamic model is adopted in this work because of important advantages of peridynamics in allowing autonomous crack initiation and propagation. A recently proposed peridynamic fatigue crack model is considered …

Applications Of Femtosecond Laser Processed Metallic Surfaces: Leidenfrost Point And Thermal Stability Of Rare Earth Oxide Coatings, Anton Charles Hassebrook

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

In this thesis, micro/nano structured surfaces were created through the use of Femtosecond Laser Surface Processing (FLSP). In the first part of the thesis, an experimental investigation of the effects of droplet diameters and fluid properties on the Leidenfrost temperature of polished and nano/microstructured surfaces has been carried out. Leidenfrost experiments were conducted on a stainless steel 304 polished surface and a stainless steel surface which was processed by a femtosecond laser to form Above Surface Growth (ASG) nano/microstructures. Surface preparation resulted in a root mean square roughness (R_rms) of 4.8 µm and 0.04 µm on the laser …

Development Of Peritoneal Microbubble Oxygenation As An Extrapulmonary Treatment For Hypoxia, Nathan Legband

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Patients affected by a respiratory disease or injury experience a substantially impaired respiratory system and as a consequence are unable to obtain a sufficient amount of oxygen. Hypoxia can quickly result in developing permanent tissue damage or death. Currently, the medical methods of treating hypoxia are mechanical ventilation or extracorporeal membrane oxygenation. However, these treatments are ineffective in certain cases and possess significant additional risks including barotrauma, infection, hemorrhage, and thrombosis.

The extrapulmonary method of peritoneal oxygenation has been investigated by other research groups as a potential alternative to providing supplemental oxygen in hypoxic animals. In peritoneal oxygenation, the peritoneum, …

On The Wetting States Of Low Melting Point Metal Galinstan And Wetting Characteristics Of 3-Dimensional Nanostructured Fractal Surfaces, Ethan Allan Davis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Exergy, or the availability of energy for useful work, is a critical issue that must be addressed to accommodate growing energy demands of society. Increasing population and steady advancement of technology necessitates novel approaches to the management, conversion, and storage of energy. Per the Lawrence Livermore National Laboratory, approximately 60 percent of the energy used by the United States in 2015 was rejected as waste [1]; a large quantity of which can be assumed to be in the form of heat. Therefore, novel thermal management methods for waste heat are critical to increasing energy efficiency and sustainability in the future. …

Near-Field Thermal Radiation For Solar Thermophotovoltaics And High Temperature Thermal Logic And Memory Applications, Mahmoud Elzouka

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This dissertation investigates Near-Field Thermal Radiation (NFTR) applied to MEMS-based concentrated solar thermophotovoltaics (STPV) energy conversion and thermal memory and logics. NFTR is the exchange of thermal radiation energy at nano/microscale; when separation between the hot and cold objects is less than dominant radiation wavelength (~1 μm). NFTR is particularly of interest to the above applications due to its high rate of energy transfer, exceeding the blackbody limit by orders of magnitude, and its strong dependence on separation gap size, surface nano/microstructure and material properties.

Concentrated STPV system converts solar radiation to electricity using heat as an intermediary through a …

Design And Validation Of An In Vivo Long-Term Attachment Capsule Robot, Wanchuan Xie

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The invention of capsule endoscopy (CE) made the non-invasive monitoring of the entire small bowel possible and became the primary means for diagnosing small bowel pathology. In the last decade, capsule robots have been transformed from diagnostic devices into a widely studied biomedical platform with the potential for active locomotion, drug delivery and therapeutic capabilities. To perform accurate on-site drug release and therapy, it is necessary for a capsule robot to be able to attach to the intestinal tissue and maintain its position long-term. Design challenges derive from the task of long-term mucosal adhesion which requires firm, quick-response attachment without …

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 …

Cfd Analysis Of Resistance Characteristics Of High-Speed Displacement Hull Forms Fitted With Hull Vane®, Venkata Karthik Avala

Theses and Dissertations

Improving the performance and resistance of a high-speed monohull forms has been of interest to Naval Architects for several decades. A considerable amount of research has been carried out in this area by using stern flaps and other appendages. This research thesis investigates the resistance characteristics of high-speed round bilge hull forms fitted with a Hull Vane® in the stern region of the vessel. The Hull Vane® is a fixed foil located below the waterline at the aft of the stern of the vessel. The Hull Vane® reduces the generation of waves at the aft and improves the vessel's motions. …

Dynamic Anchoring In Soft Regolith For Celestial Exploration, Tom Ebert

Theses and Dissertations

Recent exploration missions to celestial bodies have shown an increasing demand for surface based landers and rovers designed to perform experiments on the ground, rather than relying purely on traditional orbiting observatories. Many of the scientifically interesting locations have proven hazardous and difficult to reach and traverse, driving the need for different methods of locomotion. Some of these locations lie in deep, permanently shadowed craters or in rocky, highly uneven landscapes. Various wheeled, flying, jumping and legged rovers have been proposed, some of which have been implemented with success and problems alike. Even though the Curiosity rover has the largest …

Fast Neutron Detection In Nuclear Material Photofission Assay Using A 15 Mev Linear Electron Accelerator, Matthew Steven Hodges

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to use a 15 MeV (K15 model by Varian) linear electron accelerator (linac) for the photon assay of special nuclear materials (SNM). First, the properties of the photon radiation probe were determined. The stochastic radiation transport code, MCNP5, was used to develop computational models for the linac. The spectral distribution of photons as well as dose rate contour maps of the UNLV accelerator facility were computed for several linac operating configurations. These computational models were validated through comparison with experimental measurements of dose rates.

The linac model was used to simulate the photon interrogation …

Optimization Under Uncertainty For Wake Steering Strategies, Julian Quick, Jennifer Annoni, Ryan King, Katherine Dykes, Paul Fleming, Andrew Ning

Faculty Publications

Wind turbines in a wind power plant experience significant power losses because of aerodynamic interactions between turbines. One control strategy to reduce these losses is known as 'wake steering,' in which upstream turbines are yawed to direct wakes away from downstream turbines. Previous wake steering research has assumed perfect information, however, there can be significant uncertainty in many aspects of the problem, including wind inflow and various turbine measurements. Uncertainty has significant implications for performance of wake steering strategies. Consequently, the authors formulate and solve an optimization under uncertainty (OUU) problem for finding optimal wake steering strategies in the presence …

Refurbished And 3d Modeled Thermal Vacuum Chamber, Lauren M. Glenn

Master's Theses

Spacecraft testing includes acoustics, vibrations, and thermal vacuum. Cal Poly’s Space Environments Lab is equipped with multiple vacuum chambers, but no thermal vacuum chamber. The purpose of this thesis is to incorporate an ATS Chiller system with the HVEC vacuum chamber so students are able to experiment with a thermal vacuum chamber. The ATS Chiller had leaky pipes that needed to be refurbished and a shroud was implemented to improve thermal capabilities of the system. The full system was able to reach temperatures as low as -38ºC and as high as 58ºC at a pressure of 10-6 Torr. The ATS …

Supercritical Carbon Dioxide Extraction, Kevin Carney

Master's Theses

The objective of this thesis is to explore the properties of supercritical carbon dioxide (CO₂). In addition, the feasibility of building a small-scale low cost system will be explained. A supercritical fluid is a fluid which exhibits properties between liquid and gas with liquid like densities and viscosities similar to a gas. Since the discovery of supercritical fluids in 1822, the use of supercritical fluids, specifically supercritical CO₂, has grown in popularity. The application of supercritical CO₂ has continued to grow in industrial applications since the 1970’s. Supercritical CO₂’s has many beneficial properties …

Semi-Annual Program Progress Performance Report For University Transportation Systems Pppr#7, Florida Solar Energy Center, David L. Block

FSEC Energy Research Center®

The Electric Vehicle Transportation Center (EVTC) supports the U.S. Department of Transportation's strategic goal of planning for near-term integration of alternative fuel vehicles as a means to build a sustainable transportation system. The project objectives are to evaluate technologies, standards, planning and policies to ensure seamless integration of electric vehicles (EVs) into a complex transportation network and electricity grid. The EVTC bridges the gap between deployment of electric vehicles and the traditional transportation system. This document is a summary of the activities until April 28, 2017.

Analysis Of Tool Wear And Tool Life Of Cutting Tool Inserts Using Statistical Process Control Charts: A Case Study, Evan R. Ferrell

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Evan R. Ferrell on April 28, 2017.

Kinematics Of The Lower Extremities During Fundamental Martial Arts Tricking Techniques, Kevin P. Grassie

Honors Scholar Theses

Martial Arts Tricking (MAT) is a relatively new sport that combines martial arts, gymnastics, acrobatics, and breakdancing for the purposes of creating aesthetic and impressive combinations of kicks, flips and twists. It has been growing exponentially through social media and the overall athletic and entertainment communities. The sport is very unique in that the movements, with their blended influences, provide novel ways for athletes to generate and utilize their momentum in a creative way. The results often include off-axis flips and twists, single-leg landings, and complicated yet fluid techniques that easily chain together.

Due to the sport only being a …

Next Steps For Mentoring Program, Patrick Gray

Sustainability and Connectivity

This file provides a jump-off position for students in the fall 2017 semester who want to continue work toward a mentoring program.

Lean Process Improvement And Quality Analysis For Performance Rework, Paula R. Sloas

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the degree of Master of Science by Paula R. Sloas on April 19, 2017

Mapping And Integrating Value Creation Factors With Life-Cycle Stages For Sustainable Manufacturing, P. Bilge, S. Emec, G. Seliger, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Instead of implementing each element individually, engineers must be aware of multiple interactions among all major value creation factors and their life-cycle stages. Interactions are analyzed by a set of factors and hierarchical levels within a production system based on empirical observations and described in analytical models. Such analyses and missing information about the current condition of the system and its parts remain limited to addressing specific aspects of interactions among factors and stages for multiple decision making. To build a case-based scope addressing the interactions among a set of factors and life-cycle stages, a comprehensive approach for mapping and …

Biogas Separator And Storage Tank, Brandon Nimtz

Honors Theses

The general concept of this project is to design, simulate, and build a biogas separator system that will also store the separated methane and carbon dioxide within pressure vessels. This system is constructed of many subcomponents that will combine to separate the biogas and store the methane (CH4) and carbon dioxide (CO2). The components included in the project consist of a liquid-gas separator vessel, two heat exchangers, one methane gas compressor, and one pressure vessel each to hold methane and carbon dioxide each. While the base goal in this project was to design and simulate the necessary parts to theoretically …

Design Of A Cubesat Separation Mechanism, Ross Hiller

Honors Theses

CubeSats are compact, relatively inexpensive satellites that are often used for space research. In order to perform research related to electric propulsion devices, the Western Aerospace Launch Initiative (WALI) requires a medium-sized CubeSat capable of separating into two bodies while in orbit. Intentional separation is not common in CubeSats, so two original concepts were designed and simulated using 3D CAD and finite element analysis software. These designs were compared based on factors including weight, cost, size, and their potential to fail due to creation of debris or binding between components, in order to determine which will more effectively execute the …

Reprinter, Christian Brower

Honors Theses

Additive manufacturing (3D printing) is a rapidly growing technology, though, expensive printing filament and wasted material make it less affordable and an unsustainable process. The RePrinter combats these issues by recycling scrap 3D printed plastic parts and household plastics, such as pop bottles, and creates filament for fused deposition modeling (FDM). This product is a fully automated system which grinds, extrudes, and spools the filament for immediate use in FDM. The RePrinter works to control the extrusion speeds and tensions to optimize precise filament dimensions for quality 3D printing, while delivering the product in a timely cost effective manner.

Design And Comparison Of Variable-Stiffness Compliant Joints For Haptic Devices, David Usevitch, Mark Colton

Journal of Undergraduate Research

Haptic interfaces or devices are computercontrolled robotic systems that seek to replicate the touch experience of a human user¹. The purpose of this research is to develop a viable variable-stiffness compliant joint for haptic interfaces that eliminate rotation joints or screw mechanisms that induce friction, increase weight and cost, and make devices more complex and prone to failure. The resulting compliant haptic device was designed with both affordability and dependability in mind, and hopes to result in research knowledge leading to realistic touch experiences as users interact with virtual or remote environments. The joint may also be applicable …