Engineering Commons^™

Microparticle Propulsion For In Vivo Navigation, Louis Rogowski

Mechanical Engineering Research Theses and Dissertations

Microscale propulsion impacts a diverse array of fields, with simplistic microrobots allowing for novel innovations in microscale surgery and drug delivery. Propulsion at the microscale is constrained by physics, with time-reversal and geometric symmetries limiting available propulsion mechanisms. However, certain fluid environments and surface coatings allow for the propulsion of microparticles through externally applied magnetic fields. Presented here is a detailed analysis of microparticles propelling using spontaneous symmetry breaking, flagella surface coatings, and multi-modal actuation mechanisms. Spontaneous symmetry breaking in nonlinearly viscoelastic fluids is presented for the first time in literature, with two equal and opposite propulsion states existing along …

Fabrication Of Binder-Free Electrodes Based On Graphene Oxide With Cnt For Decrease Of Resistance, Di Zhang

Masters Theses

In electrode double layer capacitor (EDLC), electrodes usually contain binder materials to provide adhesion between electrode materials. However, binder materials usually bring unwanted resistances to the component due to their non-conductivity properties and the occupation of ion cavities. The purpose of this thesis is to demonstrate the feasibility of fabricating electrodes for EDLCs by using carbon nanotubes (CNTs) and graphene oxide (GO) without using any binding materials. At the same time, investigating the binder-free electrode’s electrochemical properties and make an assumption of its potential application in the future.

The slurry of binder-free electrodes was fabricated by ultrasonicating water suspended CNTs …

A Numerical And Experimental Study Of Lid Driven Square Cavity Flow For Laminar And Turbulent Cases, Abdullah Bin Naeem

University of New Orleans Theses and Dissertations

Experimental and numerical studies are performed on steady and unsteady lid-driven cavity flow for laminar flow regime. In the experiments, a PIV and an LDA were employed to measure the global and local velocities, respectively inside a cavity of AR 1.0. The velocity vector plots and streamline plots which represent unsteady circulation patterns are obtained using the PIV. The steady local velocities measured with LDA are then used to calibrate the PIV measurements. The numerical study is performed using a commercial CFD solver. For turbulent flow simulation RANS equations with K-Epsilon closure model were used. From the PIV calibration study, …

Performance Improvements For Next Generation Falling Particle Receiver Systems, Nathan R. Schroeder

Mechanical Engineering ETDs

Falling particle receiver (FPR) systems are a rapidly developing technology for concentrating solar power applications. Solid particles are used as both the heat transfer fluid and thermal energy storage media. Through the direct solar irradiation of the solid particles, flux and temperature limitations of tube-bundle receives can be overcome leading to higher operating temperatures and energy conversion efficiencies. Particle residence time, curtain opacity, and curtain stability affect the performance of FPR designs. As the particles fall through the receiver the curtain accelerates, increasing its transmissivity thus decreasing the amount of energy absorbed. Multistage release trough structures catch and release the …

Vibration Behavior In Modulated Tool Path (Mtp) Turning, Ryan William Copenhaver

Doctoral Dissertations

This project studies the process dynamics and surface finish effects of modulated tool path (MTP) turning. In MTP turning, a small amplitude (typically less than 0.5 mm), low frequency oscillation (typically less than 10 Hz) is superimposed on the feed motion by the machine controller to intentionally segment the traditionally long, continuous chips. The basic science to be examined is the vibration behavior of this special case of interrupted cutting, which is not turning because the chip formation is intentionally discontinuous and is not milling because the time-dependent chip geometry is defined by the oscillatory feed motion, not the trochoidal …

Characterization Of A Digital Holography Diagnostic For In Situ Erosion Measurement Of Plasma-Facing Components In Fusion Devices, Cary Dean Smith

Doctoral Dissertations

Fusion energy devices, particularly tokamaks, face the challenge of interior surface damage occurring over time from the heat flux of the high-energy plasma they generate. The ability to monitor the rate of surface modification is therefore imperative, but to date no proven technique exists for real-time erosion measurement of planar regions of interest on plasma-facing components in fusion devices. In order to fill this diagnostic gap, a digital holography system has been established at ORNL [Oak Ridge National Laboratory] for the purpose of measuring the erosion effects of plasma-material interaction in situ.

The diagnostic has been designed with the …

Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez

Boise State University Theses and Dissertations

The growing demand for clean water supplies is driving the need for an innovative approach of water desalination. Developing a method for treating water with high salinities is possible with membrane distillation (MD). Additionally, MD is very attractive for pairing with solar energy due to the low temperature requirements. The integration of a membrane distillation system with a photovoltaic (PV) system will result in the co-production of electricity and clean water, thereby improving the economics of MD. Such a hybrid system will directly absorb thermal energy in the membrane for desalination while taking advantage of the spectrally selective nature of …

Investigating Localized Performance And Mass Transport Phenomena In Polymer Electrolyte Water Electrolyzers, Frida Helena Roenning

Masters Theses

In the face of increasing demand for renewable energy sources to replace fossil fuels, current technologies face the issue of steady energy supply from source to power distribution. As most current renewable energy methods either rely on intermittent natural sources or are geographically bound, they require an energy storage medium. Polymer Electrolyte Water Electrolyzers are a theoretically ideal solution to this demand, but they require some performance improvements in practice to be economically viable. This study analyses the current distribution in such electrolyzers in the aim of gaining insight to improve their performance. The current distribution diagnostic can capture local …

Improvement Of Labyrinth Seal Leakage Rates Using Additive Manufacturing, Austin L. Gasbarra

Master's Theses

The growing popularity of additive manufacturing in commercial applications has al- lowed for new ideas and new ways of thinking when designing components. Further optimization at the component level is possible, though powder metallurgy is in its infancy. This study explores the possibility of using additive manufacturing to develop better labyrinth seals in turbomachinery. Labyrinth seals have a torturous fluid path with high losses, thus limiting the amount of fluid leakage. These types of seals can be non-rotating, allowing them to better take advantage of the additive manufacturing process due to the absence of rotating stresses. Labyrinth seal performance is …

A.C. Moyer Eye-Cap Manufacturing, Thais Bertolus, Alexa Steidl, Hana Welsh, Jarod Kinney, Maya Willis

Mechanical Engineering

A.C. Moyer company has been making eye caps as a family business since 1947. Eye caps are a product used during the embalming process. Currently the machines being used to produce the eye caps are outdated and unsafe. We are a team of 5 mechanical engineering students tasked with either designing new machines or updating the existing machines to make the manufacturing process more efficient, automated, and safer. This document describes the design process, provides background, relevant research, establishes project objectives, and defines plans for project implementation.

Centrifugal Microfluidic Platform For Solid-Phase-Extraction (Spe) And Fluorescence Detection Applications, Yong Zhang

LSU Doctoral Dissertations

Solid phase extraction (SPE) is a widely used method to separate and concentrate the target molecules in liquid mixture. Traditional SPE has to be conducted in the laboratory with professional equipment and skilled operators. The microfluidic and 3D printing technology have opened up the opportunity in developing miniaturized automatic instruments. The main contribution of this research is to integrate the SPE process on a novel centrifugal platform. Various valves are applied on the platform to help control the aqueous sample and reagents in the cartridge.

First, a centrifugal microfluidic platform was built for automatically detecting trace oil pollution in water. …

Portable Wind Turbine Blade Leading Edge Erosion Test, Joe Blakewell, Tim Holt, Kevin Vartan

Mechanical Engineering

Turbine Technology Partners, LLC (TTP) is a company located in Santa Barbara, California that provides expert independent engineering (IE) consulting services to the wind energy industry - supporting its goal of generating cost effective and reliable carbon-free renewal energy for the world. TTP customers include some of the largest wind turbine original equipment manufacturers (OEMs), wind turbine power plant developers, and wind turbine owner/operators. One of the biggest problems challenging the wind energy industry currently is the power loss that results from the leading edge (LE) erosion of wind turbine blades. The purpose of our senior design project is to …

Bolted Flanged Assembly Test Stand, Mark Christian Damasco Sunga, Paulina Mercedez Delgado, Philip John Coleman

Mechanical Engineering

The following Final Design Report (FDR) is the last formal documentation for the senior design project. The project was carried out by three senior mechanical engineering students at California Polytechnic State University, San Luis Obispo for Phillips 66. The project proposed was to design a test stand and implement a procedure which will evaluate craftsmen’s abilities to assemble a bolted flanged joint assembly. The goal was to create a fully functional test setup that can be duplicated and utilized throughout Phillips 66’s refineries. This document details the design process that was completed over the course of three quarters, including concept …

Deep-Sea Water Collector, Chandler Jones, Jenny Verheul, Michael Di Giorgio

Mechanical Engineering

Properties such as nutrients, DNA, pH levels, and primary productivity are difficult to measure onboard an Underwater Remotely Operated Vehicle (UROV) as mobile submarine sensors are highly expensive and conventional water capture devices are too large to be equipped. However, these properties provide an integral view into our oceans, the species that inhabit them, and our influence on the environment. Collected samples of seawater taken back to labs allow researchers to see a clearer picture of ecosystems’ inhabitants and lifecycle with the analysis of Environmental DNA (eDNA) among many other properties. The scope of this project is to design a …

Experimental Modelling Of Downburst And Downburst Line Outflows, Kyle Graat

Electronic Thesis and Dissertation Repository

The outflow velocity vector fields of simulated stationary thunderstorm downbursts and downburst lines were resolved in two plane orientations, vertical and horizontal, using a dense fluid release system and Particle Image Velocimetry. Single event releases were scaled to show agreement with past studies based on radial velocity magnitude and location and radial and vertical front propagation. The vortex trajectory of a single event using the vortex aspect ratio supported density's role in the outflow after the time and location of the maximum radial velocity. The interaction between two release events varied temporally and spatially and showed that the interaction region's …

Modeling Airflows And Voc Source Strengths For An Occupied School, Brett Stinson

University Honors Theses

Volatile organic compounds (VOCs) are a group of air pollutants that can adversely impact human health, engage in chemistry indoors, and meaningfully degrade indoor and outdoor urban air quality. While extensive research with regard to VOC emission rates from indoor sources has been conducted, it was not until recently that this work began to focus on characterizing emissions from humans and human activity in depth. As buildings are constructed to be increasingly airtight, and the materials utilized are chosen to reduce VOC emissions, it follows that human contributions are poised to become increasingly important indoor sources of VOCs. Utilizing data …

The Effect Of Free-Stream Turbulence On Turbulent Boundary Layers And Convective Heat Transfer From Flat Plates, Ivian Carolina Alfaia De Magalhaes

Electronic Thesis and Dissertation Repository

The present work investigates the effect of free-stream turbulence (FST) on turbulent boundary layers and forced convective heat transfer from flat plates. High resolution, 2-D and 3-D, steady Reynolds-Averaged Navier-Stokes (RANS) simulations using Computational Fluid Dynamics (CFD) techniques were performed to analyze the influence of different free-stream conditions, such as turbulence intensity (TI), integral length scale (L_u) and free-stream velocity (U_o) on local and total skin friction and convective heat transfer coefficients (CHTC), as well as on turbulent boundary layer parameters (boundary layer thickness and momentum thickness). The present study shows that …

Feasibility Study On Environmental Protection Reform Of Ship Stern Tube System Based On Water Lubrication, Yang Cui

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

The Study Of Bubble Growth Hydrodynamics In The Supersaturated Liquids, Raj Kumar Nayak Maloth

Electronic Thesis and Dissertation Repository

Bubble formation and dissolution have a wide range of industrial applications, from the production of beverages to foam manufacturing processes. The rate at which the bubble expands, or contracts has a significant effect on these processes. In the current work, the hydrodynamics of an isolated bubble expanding due to mass transfer in a pool of supersaturated gas-liquid solution is investigated. The complete scalar transportation equation (advection-diffusion) is solved numerically and it has been observed that the present model predicted an accurate bubble growth when compared with existing approximated models and experiments. The effect of gas-liquid solution parameters such as inertia, …

Homogenization Of Composite And Cellular Materials Incorporating Microstructure And Surface Energy Effects, Ahmad Gad

Mechanical Engineering Research Theses and Dissertations

In the last few decades, the popularity of composite and cellular materials has rapidly increased through their widespread applications in multiple engineering fields including aerospace, automotive, civil and biomedical. However, to a large extent, the success of their practical applications depends on our ability to predict their mechanical behavior by using high-fidelity mechanics models.

Micromechanical modeling of composite and cellular materials is a challenging task due to the heterogeneous nature of such materials and the interactions among various constituent phases at the microscopic level, which result in non-homogeneous deformation, strain and stress fields. Therefore, it is necessary to develop simple …

Formula Sae Monocoque Chassis Development, Kc Egger, Brian Ford, Kyle Nagao, Neal Sharma, Donovan Zusalim

Mechanical Engineering

Formula SAE is a collegiate competition hosted by SAE International with the primary goal being to design, manufacture, and race an open wheel race car. The Cal Poly Racing Formula SAE team strives for improvement every race season and has remained competitive as a result. The 2019-2020 management team determined that further research and development towards the chassis would yield the greatest performance benefit for future seasons, as the previous chassis platform limited packaging and mounting options for vehicle subsystems which interfaced with the chassis.

A redesign of the Cal Poly Racing Formula SAE team’s carbon fiber reinforced polymer monocoque …

Aqueous Redox Flow Batteries With Boron Doped Diamond As An Electrode., Alex M. Bates

Electronic Theses and Dissertations

As the interest and implementation of renewable energy accelerates, so does that of grid energy storage. It is widely believed that a cost-effective energy storage technology will bring about the proliferation of renewable energy. Redox flow battery (RFB) technology represents a promising solution to cost-effective grid energy storage. Compared to other technologies, RFBs have a long lifetime, high efficiency, are non-flammable, significantly reduce cost, and separately scale power and energy. The separation of power and energy enables increased energy capacity by simply adding electrolyte volume. Of the challenges facing RFB technology, one readily apparent is the cost of the active …

Experimental Investigation Of Flow And Thermal Behavior In Channels With Pcm-Filled Thermal Energy Storage Columns For Potential Application In Photobioreactors, Kira Toxopeus

Electronic Thesis and Dissertation Repository

Microalgae has been identified as a potential source for the production of biofuels and other bio-products. The growth of microalgae is sensitive to the temperature variations inside the photobioreactor. The present research investigated an innovative approach to thermally regulate photobioreactors by introducing passive thermal energy storage using phase change material (PCM). The research was specifically focused on a novel design to integrate thermal storage in the reactor channel in the form of offset columns containing PCM. Two column shapes were considered: circular and square. The first part of the study was focused on characterizing the influence of offset column shapes …

Cp Check Valve Design, Alec B. Der Matoian, Jessica M. Dent, Skylar M. Tusting

Mechanical Engineering

This report is to serve as a final design review and update to the project sponsors at Zurn Wilkins for the Check Valve Design Senior Project. The senior project team was tasked with improving upon the design of Zurn Wilkins’ backflow prevention assembly for small diameter pipes by reducing the pressure loss created by the check valves within the double check backflow assembly. The information contained in this report builds off the information contained in the Critical Design Report (CDR), as well as feedback and further investigation suggested during an Intermediary Design Review. Based on conclusions from the CDR, our …

Raysun's Infrared Raisin Dryer, Lucas Kensinger, Saraith Aispuro, Joe Vanacore

General Engineering

The RaySuns senior project team was tasked with lowering the drying costs of raisins for River Ranch Raisins. In doing so, we explored several options for cutting costs: utilizing automation and exploring new drying technologies were our primary focus. We eventually planned a modular infrared heating mechanism which would be easy to automate in future projects. After manufacturing and testing an infrared heating mechanism, it was found that infrared drying could significantly cut costs versus the previous natural gas fired dryer tunnels while leaving room for automation. The infrared dryer was also shown to have the potential to create high-quality …

Design For Additive Manufacturing, Michael Charonnat, Leonardo Franco-Muñoz, Sam Noble, J.P. Purdom

Mechanical Engineering

This document outlines the critical design details and timeline for the Design for Additive Manufacturing Senior Project sponsored by Solar Turbines, Inc. The scope of this project encompasses the redesign of two of Solar Turbine’s cast parts for metal additive manufacturing in order to minimize lead time, cost, and weight. With the overall objective of performing in-depth analysis exploring affordability & feasibility, this redesign process will aid Solar Turbines in expanding their knowledge of Design for Additive Manufacturing principles and enable them to further incorporate the use of additive manufacturing into their production processes. The first part that the team …

Optical Filter Selector, Camaryn Chambers, Joel Pitzer, Matthew Allen, Callen Schwefler

Mechanical Engineering

One of the many challenges with launching projectiles into space is predicting how the environment in space will affect the trajectory. One way to do this is to look at optical emissions, also known as airglow, which can only be seen from earth with sensitive equipment. By taking measurements of the light from the airglow, properties about the upper atmosphere can be inferred. This is important because variability in the atmosphere can cause variability in space that can affect astronauts and satellites. In order to accomplish this task, optical filters must be used to observe different bands of wavelengths of …

Atmospheric Water Harvester, Justin K. Lam, Jacob David, Jessica Mabry, Ben Brough

Mechanical Engineering

Atmospheric water harvesting uses the vapor-compression cycle to collect water from the moisture in the air. The system’s components include an evaporator, condenser, compressor, fan, and several expansion valves. Condensate from the air is then funneled into a receptacle, which determines the efficiency of the water harvesting system. For this senior project, the goal is to increase the efficiency of an existing atmospheric water harvester.

Rsvp Spaceship!, Taylor Chavez, Deven Frauenhofer, Andrew Nott, Zoe Riesen

Mechanical Engineering

This document outlines the Final Design Review of a mechanical engineering senior design project at California Polytechnic State University San Luis Obispo. The project was to design and build a spaceship prop that will deploy during the performance put on by the Sound Design program within the Music Department. This performance, RSVP, is in its 25th year. Dr. Antonio G. Barata, the artistic director and producer of RSVP, is sponsoring the project. The key constraints include keeping the prop hidden in a confined space (under a stage that is comprised of multiple 4 ft. by 8 ft. by 3 ft. …

Numerical Methods For Predicting The Dynamic Crushing Response And Energy Absorption Of Composite Aluminum Honeycomb Sandwich Structures, Cody R. Volk

Master's Theses

Edgewise crushing responses of composite aluminum honeycomb sandwich structures were predicted using finite element analysis (FEA) software LS-DYNA by modeling the honeycomb as a material with anisotropic properties. The goal of the project was to develop a process for modeling the sandwich structure to rapidly iterate possible solutions for a safer workstation train table. Current workstation tables are too rigid and may cause injury or death in a head-on collision. Experimental compression tests were used to calibrate the aluminum honeycomb core with material type 26 (MAT 26, honeycomb). A published composite tensile test was used to validate the use of …