Mechanical Engineering Commons^™

Final Project Report: Heliostat-Concentrator Solar Cooker, Ian Davison, Devin Mast

Mechanical Engineering

This document is the full report for the senior project of Cal Poly Mechanical Engineering students Ian Davison and Devin Mast. The report encompasses the full project process, including background research, identification of need, design requirements, design development, proposed design, design realization, changes to proposed design, and design verification. We were tasked with the design and manufacture of a “dual mirror” solar cooker to verify a concept for a new type of off-axis parabolic solar cooker conceived by Dr. Pete Schwartz, the sponsor of the senior project and a physics professor at Cal Poly. Previously, off-axis parabolic solar cookers have …

Development Of A Set Of Force Response Equations To Represent The Musculature In Infants To Study Development Dysplasia Of The Hip, Brendan Jones

HIM 1990-2015

This paper describes how a force response equation was created to model muscles, tendons, and ligaments of the hip joint to improve a biomechanical model of an infant hip to study Developmental Dysplasia of the Hip (DDH). DDH is the most common abnormality in newborn infants and is defined as any amount of instability in the hip including complete dislocation. Researchers at our institution are attempting to increase the success rate of treatment methods by creating computer models of the biomechanics of infant hip instability and dislocation. The computer model used a scaled adult pelvis, femur, tibia, fibula and foot …

Design Of A Physical Windkessel Model For Use In Lvad In-Vitro Benchtop Modeling, Kyle W. Beggs

HIM 1990-2015

Despite improved life expectancy compared to medical management alone, Ventricular Assist Device (VAD) recipients show survival rates of 80% at 12 months and 70% at 24 months. A large portion of VAD-associated mortality results from increased risk of stroke with an event frequency reported between 14-47%. Recent concerns have been raised about unprecedented increases of thrombus formation in VAD recipients with subsequent reports pointing towards implantation techniques as a critical contributor to these events. Thus, the overall prognosis with mechanical support can improve by advancing the surgeon’s approach to VAD implantation. Previous studies using Computational Fluid Dynamics (CFD) were aimed …

Effects Of Binary Solvent System On Morphology Of Particles, Patrick Besana

HIM 1990-2015

Recent advancements in cancer research has led to the synthesis of a new drug known as docetaxel. Meant to replace paclitaxel, its more natural counterpart whose ingredients are difficult to obtain, the drug is known to effectively treat a wide array of cancers, including breast cancer, ovarian cancer, and prostate cancer. The establishment of a synthetic alternative to paclitaxel has increased its bioavailability, thereby lowering the cost needed to utilize the drug. Still, the limiting factor in minimizing costs is the method in which the drug is processed. Current methods in drug processing have their limitations, which include the introduction …

Comments On “The Principal Axes Decomposition Of Spatial Stiffness Matrices”, Shuguang Huang, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

A significant amount of research has been directed toward developing a more intuitive appreciation of spatial elastic behavior. Results of these analyses have been described in terms of behavior decompositions and in terms of behavior centers. In a recent paper entitled “The Principal Axes Decomposition of Spatial Stiffness Matrices” by Chen et al. (IEEE Trans. Robot., vol. 31, no. 1, pp. 191-207), a decomposition of spatial stiffness was presented, and centers of stiffness and compliance were identified. The results presented in the paper have substantial overlap with previously published results and redefine previously used terms. The objective of this communication …

Springback Force Considerations In Compliant Haptic Interfaces, Dallin R. Swiss

Theses and Dissertations

This thesis investigates the potential benefits and challenges of using compliant mechanisms in the design of haptic interfaces. The benefits and challenges are presented with an emphasis on their inherent springback behavior and an active compensation approach. Design criteria for compliant mechanism joint candidates are reviewed and several joints are surveyed. Quantitative calculations of axial stiffness and maximum stress for five candidates are presented. Generalized analytical models of springback force and compensation torque are created to simulate the implementation of each joint candidate in a two degree-of-freedom planar pantograph. We use these models in the development and discussion of an …

Elucidating The Mechanisms Of Rate-Dependent Deformation At Ambient Temperatures In A Model Metallic Glass, Matthew Bradley Harris

Theses and Dissertations

In this work, the Shear Transformation Zone (STZ) dynamics model is adapted to capture the transitions between different regimes of flow serration in the deformation map of metallic glass. This was accomplished by scaling the STZ volume with a log-linear fit to the strain rate, and also adjusting the activation energy of an STZ with a log-linear fit to maintain constant yield strength at differing strain rates. Twelve simulations are run at each of six different strain rates ranging from 10^-5 to 10⁰ s^-1, and statistics are collected on simulation behavior and shear band nucleation and …

Effects Of Various Mobility Aids On Lower-Extremity Muscle Activity, Michael Ryan Sanders

Theses and Dissertations

Millions of people each year spend some portion of their time using mobility aids to facilitate periods of non-weight bearing ambulation. The use of these devices changes the loading conditions of the lower extremities, which may result in skeletal muscle adaptations. The purpose of this work was to evaluate the effects of 3 types of mobility aids on lower-extremity muscle activity. Evaluation was based on 1) measured muscle activation signals using electromyography (EMG), and 2) measured joint kinematics and ground reaction forces, which were used to predict muscle forces. 16 healthy subjects (7 female, 9 male), ages 18-27 participated in …

Underwater Rope Fatigue Testing Machine, Napoleon Nino, Andrew Pimentel

Mechanical Engineering

The design and fabrication of an underwater rope fatigue testing machine meant to simulate the effects of an oceanic environment and the effects on rope.

Thermal Hydraulic Turbine Dynamometer, Ryan Baskett, Alexander Campbell, Andrew Puntorno-Carlberg

Mechanical Engineering

No abstract provided.

Child Carrier: Senior Project, Cordell Hollingsworth, Jacob Puppo, Drew Sapp

Mechanical Engineering

No abstract provided.

Tron 2.0 - The Experience, Alecsandro G. Vitale, Alexander W. Billings, Jordan Delfino, William Beechinor, Kelly Rorden

Architectural Engineering

The goal of this senior project was to come up with a structural-engineering-related schematic design for a roller coaster to be installed in Disneyland called TRON 2.0: The Experience. This involved looking at both design processes that we had already learned through our curriculum as well as researching concepts that were previously foreign to us, namely the dynamic application of loads and the effects of fatigue stresses.

A story was established based on the source material: the TRON movies produced by Walt Disney Studios. Thematic elements from the story were used as the basis for design implications that would become …

High Temperature Hepa Filter Test Unit Upgrades, Alexander Krippner, Ian Corcorran, Michael Burlando

Mechanical Engineering

No abstract provided.

High Speed Jet Turbine Test Final Report, Kenneth Enstrom, Cameron Naugle, Isaac Thomas, Cody Lee

Mechanical Engineering

At high flight altitudes and speeds, external airplane elements are subject to immense loads. External devices must be put through testing that simulates these loads to ensure safety of the device. Our system will subject a device in need of testing to a jet of air, similar to wind seen on the surface of an airplane. The High Speed Air Jet Turbine Test project team has been tasked to design, build, and test an apparatus capable of acquiring real world flight data for micro-ram air turbines (microRAT). The micro-RAT is a device that provides power to an electrical device by …

Modeling The Residual Useful Life Of Railroad Bearing Grease, Thania Alejandra Martinez

Theses and Dissertations

Railroad bearing performance is often constrained by the life of its lubricant. The lubricant life is determined by tribomechanical processes that are present during bearing operation. No known physical models exist to predict the railroad bearing lubricant life. This thesis summarizes the efforts undertaken in the development of empirical models that can accurately predict the residual useful life of railroad bearing grease. Modeling techniques to be employed include regression, regression trees, and split plots. The grease samples used to populate this model come from healthy and faulty bearings that were run under different loads, speeds, and ambient conditions in a …

Pressure Field Estimation Using Particle Image Velocimetry, Jean O. Calzada

Theses and Dissertations

In recent years, scientist and engineers have shown the advantages created by using the Particle Image Velocimetry (PIV) method as flow diagnostic tool to characterize instantaneous velocity fields. One of the important benefits is found on its non-intrusive nature, this leads to accurate velocity fields. From the velocity field obtained by PIV important quantities can be derived, such as pressure and vorticity. The present study, uses PIV data of an incompressible turbulent pulsed jet to determine the pressure field associated with the flow field. The pressure is calculated by using the averaged velocity field along with three different fundamental equation: …

Sparse Aperture Speckle Interferometry Telescope Active Optics Control System, Matthew Clause

Master's Theses

A conventional large aperture telescope required for binary star research is typically cost prohibitive. A prototype active optics system was created and fitted to a telescope frame using relatively low cost components. The active optics system was capable of tipping, tilting, and elevating the mirrors to align reflected star light. The low cost mirror position actuators have a resolution of 31 nm, repeatable to within 16 nm. This is accurate enough to perform speckle analysis for the visible light spectrum. The mirrors used in testing were not supported with a whiffletree and produced trefoil-like aberrations which made phasing two mirrors …

In Vitro Multi-Scale Patient-Specific Modeling Of Hemodynamics In Stage 1 Norwood Palliation For The Treatment Of Single Ventricle Heart Disease, Tianqi Hang

All Dissertations

Hypoplastic left heart syndrome (HLHS) is a congenital heart defect in which the left ventricle is severely underdeveloped. The Norwood procedure is the first stage procedure to make an unrestrictive systemic blood flow and at the same time balance it with the pulmonary flow. This is done by constructing a neo-aorta using the pulmonary artery root and the autologous aorta, and then installing a shunt to the pulmonary artery. Variations of the Norwood surgery include the modified Blalock-Taussig (mBT) shunt, which diverts blood from the innominate artery to the pulmonary artery (PA), and the Right Ventricle Shunt (RVS), which diverts …

Electromechanical Modeling Of A Honeycomb Core Integrated Vibration Energy Converter With Increased Specific Power For Energy Harvesting Applications, Nataraj Chandrasekharan

All Dissertations

Innovation in integrated circuit technology along with improved manufacturing processes has resulted in considerable reduction in power consumption of electromechanical devices. Majority of these devices are currently powered by batteries. However, the issues posed by batteries, including the need for frequent battery recharge/replacement has resulted in a compelling need for alternate energy to achieve self-sufficient device operation or to supplement battery power. Vibration based energy harvesting methods through piezoelectric transduction provides with a promising potential towards replacing or supplementing battery power source. However, current piezoelectric energy harvesters generate low specific power (power-to-weight ratio) when compared to batteries that the harvesters …

Characterizing The Effective Bandwidth Of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria, Meghashyam Panyam Mohan Ram

All Dissertations

In the last few years, advances in micro-fabrication technologies have lead to the development of low-power electronic devices spanning critical fields related to sensing, data transmission, and medical implants. Unfortunately, effective utilization of these devices is currently hindered by their reliance on batteries. In many of these applications, batteries may not be a viable choice as they have a fixed storage capacity and need to be constantly replaced or recharged. In light of such challenges, several novel concepts for micro-power generation have been recently introduced to harness, otherwise, wasted ambient energy from the environment and maintain these low-power devices. Vibratory …

On Subgrid-Scale Physics In The Convective Atmospheric Surface Layer, Khuong Nguyen

All Dissertations

The dynamics of the subgrid-scale (SGS) stress and scalar flux in the convective atmospheric surface layer are studied using field measurements from the Advection Horizontal Array Turbulence Study (AHATS). We extend the array technique previously used to evaluate the SGS velocity and temperature to include measurements of the fluctuating pressure, enabling separation of the resolvable- and subgrid-scale pressure and allowing for the first-ever observations of the pressure covariance terms and the full SGS budgets. Non-dimensional forms of the budget terms are analysed as functions of the surface-layer stability parameter and the ratio of the wavelength of the spectral peak of …

Impact Of Constructing A Low Crested Weir In Cape Canaveral On Flushing In The Banana River, Atousa Saberi

Theses and Dissertations

The purpose of this study is to determine the extent to which constructing a low crested weir adjacent to Port Canaveral improves ushing in the Banana River. The Banana River is a 50 km long sub-basin of Indian River Lagoon (IRL), located between Cape Canaveral and Merritt Island in Brevard County. Although Port Canaveral locks connect the Banana River to the ocean, the locks remain closed when there are no passing vessels; therefore, it has limited circulation and a long ushing time. Declining water quality can be linked to recent high mortality events of di erent species living in the …

Predicted Stresses In A Ball-Grid-Array (Bga)/Column-Grid-Array (Cga) Assembly With A Low Modulus Solder At Its Ends, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

A simple, easy-to-use and physically meaningful predictive model is suggested for the assessment of thermal stresses in a ball-grid-array or a column-grid-array with a low modulus solder material at the peripheral portions of the assembly. It is shown that the application of such a design can lead to a considerable relief in the interfacial stresses, even to an extent that inelastic strains in the solder joints could be avoided. If this happens, the fatigue strength of the bond and of the assembly as a whole will be improved dramatically: low-cycle fatigue conditions will be replaced by the elastic fatigue condition, …

An Approach To Model Plastic Deformation Of Metallic Plates In Hypervelocity Impact Experiments, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Space structures are subjected to micro-meteorite impact at extremely high velocities of several kilometers per second. Similarly, design of military equipment requires understanding of material behavior under extremely high pressure and temperature. Study of material behavior under hypervelocity impact (HVI) poses many challenges since few researchers so far have approached this problem. Material models, equations of the state, and fracture mechanics are not well understood under these conditions.

The objective of this research is to present an approach for studying plastic deformation of metallic plates under HVI conditions. A two-stage light gas gun can be used to simulate these conditions …

The Comparison Of Two Supine Manikins And The Use Of A Shock And Vibration Isolation System For Litter Patients In Air Medical Transport, Karina Karlui Saenz Acosta

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studies show that repeated shock and vibration during aero medical and ground transport are causing patient pain and may be adversely affecting patients’ medical outcome. Patients with spine and head injuries and other severe neurological injuries are the most vulnerable to repeated shock and vibration exposure caused by the vehicle. It is crucial to minimize the effects of these forces on patients during air and ground medical transport. The development of new medical evacuation platforms creates a need to better understand the effects of human exposure to shock and vibration. The use of human subjects to measure whole body vibration …

Numerical Validation Of Cooling Performance Of Phase Change Materials Integrated Into Heat Sinks For Electronics Cooling, Shaimaa Mohamed Abu Ayyan

Theses

This study aims to analyze the cooling performance of phase change materials (PCMs) integrated into metallic heat sinks (HSs) both experimentally and numerically. For the experimental part of the study, a test setup has been constructed to test PCM integrated heat sinks. The heat sinks are prepared as metallic containments having fins with fixed inter-fin spacing. The volume between the heat sink fins is filled with PCM namely: a paraffin wax, salt hydrate-calcium chloride and milk-fat, then the whole system is sealed for testing under various heat loads at 4W, 6W, 8W and 10W. Four modes of operation are experimentally …

Designing, Building And Testing A Solar Thermoelectric Generation, Steg, For Energy Delivery To Remote Residential Areas In Developing Regions, Yacouba Moumouni

UNLV Theses, Dissertations, Professional Papers, and Capstones

New alternatives and inventive renewable energy techniques which encompass both generation and power management solutions are fundamental for meeting remote residential energy supply and demand today, especially if the grid is quasi-inexistent. Solar thermoelectric generators can be a cost-effective alternative to photovoltaics for a remote residential household power supply. A complete solar thermoelectric energy harvesting system is presented for energy delivery to remote residential areas in developing regions. To this end, the entire system was built, modeled, and then validated with LTspice simulator software via thermal-to-electrical analogy schemes. Valuable data in conjunction with two novel LTspice circuits were obtained, showing …

Microstructure Alone Induced Wetting Transition From Hydrophilic To Hydrophobic On Silicon And Graphene, Henry L. Ems

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

In the present work, transition from hydrophilic to hydrophobic wetting states for an intrinsically hydrophilic surface (contact angle less than 45 degrees) using only surface microstructuring is presented. The surface microstructures are re-entrant microcavities (inverted trapezoidal microstructures) which promote air entrapment below the water droplet causing a Cassie wetting state as opposed to a Wenzel state where the surface is completely wetted. The microstructures were fabricated on a Silicon-On-Insulator (SOI) wafer through steps of deposition, photolithography, etching, and bonding. Contact angle measurements demonstrated the ability of the microfabricated surfaces to sustain large contact angles above 100°, in comparison to a …

Simulation Of An Air Cooled Single-Effect Solar Absorption Cooling System With Evacuated Tube Collectors, Mohsen Jahandardoost

UNLV Theses, Dissertations, Professional Papers, and Capstones

Consistently increasing CO2 emission and ozone depletion from synthetic refrigerants are serious environmental issues challenging the scientific community. Absorption cooling systems give scope of utilizing low grade energy source for generating cooling effect. Solar energy is one of these low grade energy sources and with considering the fact that cooling demand increases with the intensity of solar radiation, solar refrigeration has been considered as a logical solution.

This thesis consists of two different simulation stages, in the first stage, a single effect lithium bromide absorption cooling system with constant cooling capacity is modeled and the effect of ambient and generator …

Sound Attenuation Of Fiberglass Lined Ventilation Ducts, Jacob Albright

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sound attenuation is a crucial part of designing any HVAC system. Most ventilation systems are designed to be in areas occupied by one or more persons. If these systems do not adequately attenuate the sound of the supply fan, compressor, or any other source of sound, the affected area could be subject to an array of problems ranging from an annoying hum to a deafening howl. The goals of this project are to quantify the sound attenuation properties of fiberglass duct liner and to perform a regression analysis to develop equations to predict insertion loss values for both rectangular and …