Mechanical Engineering Commons^™

Investigation Of Exothermic Reaction Dynamics Via Computational Fluid Dynamics Coupled With A Feedback Controller, Siusan Choi

Mechanical and Aerospace Engineering Dissertations - Archive

The control of reaction temperature under continuous flow conditions is important in a variety of chemical manufacturing industries. For many reactions, operating at off-design temperatures can result in the production of undesired products, reduced feedstock conversion and, in some cases, reduced catalyst lifetime. In many exothermic reactions, maintaining a desired set point temperature at high reactant flow rates becomes challenging if the chemical kinetics exhibit highly non-linear behavior. In these situations, the interaction between commonly used linear controllers and the physical system can lead to unexpected dynamic response and undesired swings in reaction temperature. In this research, a computational model …

Investigation Of Digital Pump/Motor Control Strategies, Farid El Breidi

Open Access Dissertations

A pump is the heart of fluid power systems, it has a significant impact on the efficiency of many fluid power systems. Motors are the most common rotary actuators in fluid power systems. State-of-the-art pump/motor units can achieve efficiencies higher than 90% when operating at maximum displacement; however, as the displacement drops, the efficiency of these units drops to below 50%. A new digital pump/motor design aims at increasing these efficiencies by utilizing two electrically controlled high speed on/off valves per displacement chamber; these valves provide the ability to achieve variable displacement and allow freedom in choosing operating strategies. Such …

Characterization Of Impact Properties Of Forged, Layered, And Additive Manufactured Titanium Alloy, Melissa Kathryn Matthes

UNLV Theses, Dissertations, Professional Papers, and Capstones

New additive manufactured (AM) materials have the potential of optimizing the geometry and microstructure of complex components to enhance their structural integrity while creating them quickly. However, the behavior of AM materials under extreme dynamic loading conditions is not fully understood. This is especially important in many applications. For example, spacecraft components may be impacted by micrometeorites at hyper velocities of multiple kilometers per second, inducing extreme dynamic loading.

One type of AM material is created by melting and solidifying metal along a specified path. Depending on the geometry, additional streams will be deposited side-by-side. This process affects the microstructure …

The Development Of A Prosthetic Training Software For Upper Limb Amputees, Tyler Kayne Sullins

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to develop an intuitive software that aids in the field of prosthetic training and rehabilitation by creating an individualized visualization of joint angles. This software is titled “the prosthetic training software (PTS) for individualized joint angle representation”, and it enables the individualized portrayal of predicted or pre-recorded joint angles. The PTS is an intuitive program for clinicians and prosthesis users that produces an animation of a virtual avatar reflecting the user’s segment lengths and amputation for rehabilitation and training purposes.

The PTS consists of a graphical user interface (GUI) and a 3D visualization of …

Bunch Splitting Simulations For The Jleic Ion Collider Ring, R. Gamage, T. Satogata

Physics Faculty Publications

We describe the bunch splitting strategies for the proposed JLEIC ion collider ring at Jefferson Lab. This complex requires an unprecedented 9:6832 bunch splitting, performed in several stages. We outline the problem and current results, optimized with ESME including general parameterization of 1:2 bunch splitting for JLEIC parameters.

Energy Models Of The Txaire Houses, Tajudeen Amadu Annafi

Mechanical Engineering Theses

Model calibration is important as its functions improve building models. A calibrated model of the TxAIRE Houses #1 and #2 have been developed using the OpenStudio software. The model was developed and calibrated with data of the year 2014 but can be used predict electricity consumption of any year.

An actual meteorological year (AMY) weather file was also created for the houses which was used for calibration. The data used to develop this weather file were measured on-site which improved the accuracy of the model. It was found that an error difference of -1.0 % and -4.2 % occurred between …

Computational Analysis Of Impact Loading On Wafer Level Chip Scale Packages Mounted On Printed Circuit Boards Of Varying Thickness, Anik Mahmood

Mechanical and Aerospace Engineering Theses - Archive

In the electronic industry one of the popular package is Chip Scale Package (CSP) due to its small form factor and low cost. To meet the need of new functionality and portability of the recent devices, CSPs’ have been most favorable choice for a long time. On the other hand, with the miniaturization process of these portable devices there is a growing risk of drop impact failure in day to day use. It’s not only the mechanical loading that is affecting the reliability of these devices but also thermal and thermo-mechanical loads are acting simultaneously. To analyze and ensure the …

Advances In Repurposing And Recycling Of Post-Vehicle-Application Lithium-Ion Batteries, Charles R. Standridge, Lindsay Corneal, Nicholas Baine

Mineta Transportation Institute

Increased electrification of vehicles has increased the use of lithium-ion batteries for energy storage, and raised the issue of what to do with post-vehicle-application batteries. Three possibilities have been identified: 1) remanufacturing for intended reuse in vehicles; 2) repurposing for non-vehicle, stationary storage applications; and 3) recycling, extracting the precious metals, chemicals and other byproducts. Advances in repurposing and recycling are presented, along with a mathematical model that forecasts the manufacturing capacity needed for remanufacturing, repurposing, and recycling. Results obtained by simulating the model show that up to a 25% reduction in the need for new batteries can be achieved …

3d Infrastructure Condition Assessment For Rail Highway Applications, Teng Wang

Theses and Dissertations--Civil Engineering

Highway roughness is a concern for both the motoring public and highway authorities. Roughness may even increase the risk of crashes. Rail-highway grade crossings are particularly problematic. Roughness may be due to deterioration or simply due to the way the crossing was built to accommodate grade change, local utilities, or rail elevation. With over 216,000 crossings in the US, maintenance is a vast undertaking. While methods are available to quantify highway roughness, no method exists to quantitatively assess the condition of rail crossings. Conventional inspection relies on a labor-intensive process of qualitative judgment. A quantifiable, objective and extensible procedure for …

Simulation Of Scalability For Autonomous Mobile Microgrids, Nathan Beyers

Dissertations, Master's Theses and Master's Reports

Microgrids are small-scale, decentralized systems for generation, storage, and management of electricity to provide power within a local area. By establishing these microgrids using autonomous robots, they can be made safer and more easily reconfigurable. This thesis presents a plan and outlines the infrastructure needed for scaling up previous experimental work on such systems. This work brings together a variety of tools in the form of both software and hardware to set the stage for how further development can be completed. An architecture for physical testing has been built to validate the full potential of navigation and making electrical connections …

Torque Accuracy Improvement Via Explicit Torque Feedback Control For Internal Combustion Spark Ignition Engines, Anwar Alkeilani

Wayne State University Dissertations

At the present time, both control and estimation accuracies of engine torque are causes for under-achieving optimal drivability and performance in today’s production vehicles. The major focus in this area has been to enhance torque estimation and control accuracies using existing open-loop torque control and estimation structures. Such an approach does not guarantee optimum torque tracking accuracy and optimum estimation accuracy due to air flow and efficiencies estimations errors. Furthermore, current approach overlooks the fast torque path tracking which does not have any related feedback. Recently, explicit torque feedback control has been proposed in the literature using either estimated or …

Efficient Time-Dependent System Reliability Analysis, Zhifu Zhu

Doctoral Dissertations

"Engineering systems are usually subjected to time-variant loads and operate under time-dependent uncertainty; system performances are therefore time-dependent. Accurate and efficient estimate of system reliability is crucial for decision makings on system design, lifetime cost estimate, maintenance strategy, etc. Although significant progresses have been made in time-independent reliability analysis for components and systems, time-dependent system reliability methodologies are still limited. This dissertation is motivated by the need of accurate and effective reliability prediction for engineering systems under time-dependent uncertainty. Based on the classic First and Second Order Reliability Method (FORM and SORM), a system reliability method is developed for multidisciplinary …

An Invastigation Of Band-Limited Fluid Damper Configuration Using Lumped Parameter Modeling, Ye Hong

Mechanical and Aerospace Engineering Theses - Archive

Vehicle suspension system is one of the key factors related to the vehicle dynamic characteristic. The fine tuning of suspension system between vehicle handling and ride comfort is not only a trade-off between these two aspects, but also, has its impact on vehicle safety and durability. For an optimal damper performance, the damper needs to generate sufficient damping force at maneuvering frequency (< 2 Hz); and it also needs to generate less damping force, which allow spring to filter the high frequency noise (> 2 Hz) generated by vehicle travels along rough road condition at speed. In order to achieve such performance, a lumped parameter model of Band-Limited Damper is proposed. Frequency response of both Conventional Damper and Band-Limited Damper are …

Powder Compaction Simulation, Yuqi Fang, Caroline Baker, Marcial Gonzalez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Powders are one of most manipulated materials in many industries such as food, pharmaceutical, energy and metallurgical industries. An important process for the powders is the compaction into solids with small porosity or high relative density. However, powders exhibit complex behavior during this process. After rearrangement and jamming of the powder bed, many types of deformation mechanisms dominate the compaction of granular materials, including elastic and plastic deformation of each individual particle. Therefore, having a better understanding of macroscale and microscale properties of powder beds and single particles during the compaction process is necessary. In addition, to reduce cost and …

Assessment Of Critical Technologies For Gas Turbine Engines Using Numerical Tools, Vinicius Pessoa Mapelli, Guillermo Paniagua, Jorge Sousa

The Summer Undergraduate Research Fellowship (SURF) Symposium

In 2014 gas turbine engine has reached a market value of 82.5 billion dollars, of which 59.5% are related to aircraft propulsion. The continuous market expansion attracts more and more the interest of researchers and industries towards the development of accurate numerical techniques to model thermodynamically the entire engine. This practice allows a performance and optimization analysis before the actual experimental testing, reducing the time and required investment in the design of a new engine. In this paper, a recently developed open source numerical tool named “Toolbox for the Modeling and Analysis of Thermodynamic Systems” (T-MATS) is used to assess …

Simulation And Validation Of Radio Frequency Heating Of Shell Eggs, Soon Kiat Lau

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Finite element models were developed with the purpose of finding an optimal radio frequency (RF) heating setup for pasteurizing shell eggs. Material properties of the yolk, albumen, and shell were measured and fitted into equations that were used as inputs for the model. When the egg was heated by itself, heating tend to be focused at the air cell to result in a “coagulation ring.” The focused heating near the air cell of the egg prevented satisfactory pasteurization of the egg, but deeper analysis of the simulation results offered a new perspective on how non-uniform RF heating could occur in …

Traction-Separation Relationships For Hydrogen-Induced Grain Boundary Embrittlement In Nickel Via Molecular Dynamics Simulations, Wesley Allen Barrows

Graduate Theses and Dissertations

The deleterious effects of atomic and molecular hydrogen on the mechanical properties of metals have long been observed. Although several theories exist describing the mechanisms by which hydrogen negatively influences the failure of materials, a consensus has yet to be reached regarding the exact mechanism or combination of mechanisms. Two mechanisms have gained support in explaining hydrogen’s degradative role in non-hydride forming metals: hydrogen-enhanced localized plasticity and hydrogen-enhanced decohesion. Yet, the interplay between these mechanisms and microstructure in metallic materials has not been explained. Accordingly, for this thesis, the three main objectives are: (i) to develop a numerical methodology to …

Aerospike Rocket Motor Structural Webbing, Andrew Brock

Master's Theses

A labscale hybrid rocket motor test stand has been developed for research at Cal Poly. The primary focus of research using this rig has been the development of regenerative cooling techniques using nitrous oxide as coolant and oxidizer, as well as validation of technologies relating to the annular aerospike nozzle. In order to prevent undesirable deflection of the cantilevered spike, a structural stiffening web, referred to as “The Spider,” is proposed. The Spider resembles a three-spoked wheel, with the aerospike held by the inner hub and the chamber walls abutting the outer radius.

The Spider, placed upstream of the nozzle, …

Analytical And Numerical Validation Of Nozzle Spray Measurement Data Obtained From A Newly Developed Production System, Iddrisu Seidu

ETD Archive

A newly developed production test stand for measuring the spray angle of a pressure swirl atomizer was constructed and used to measure a product line of these pressure swirl atomizers -- the macrospray atomizer. This new test stand, utilizing constant temperature hot wire anemometers, captures the spray angle data based on the voltage drop the hot wire probes see as they traverse the spray cone of the atomizer and as fluid droplets impinge upon the wire. Datasets acquired from the experiments are compared and correlated with computational fluid dynamics (CFD) simulation data. In addition, angles obtained from another type of …

Dynamic Model Of A Non-Linear Pneumatic Pressure Modulating Valve Using Bond Graphs, Christopher L. Brubaker

ETD Archive

This research develops a mathematical model of the dynamic pressure response to a variable travel input of a pneumatic pressure modulating valve intended for use in a vehicle air brake system. Generically, the valve is a multi-domain system consisting of a mechanical portion and a pneumatic portion. Included in the mechanical portion of the model are compliance of the springs, inertia of the components, and resistance of the sliding components. The pneumatic portion of the model includes capacitance due to the compressibility of the gas, flow resistance through connected plumbing, and flow resistance through the valve control orifices. The development …

Combustion Kinetics Of Advanced Biofuels, Ghazal Barari

Electronic Theses and Dissertations

Use of biofuels, especially in automotive applications, is a growing trend due to their potential to lower greenhouse gas emissions from combustion. Ketones are a class of biofuel candidates which are produced from cellulose. However, ketones received rather scarce attention from the combustion community compared to other classes such as, alcohols, esters, and ethers. There is little knowledge on their combustion performance and pollutant generation. Hence their combustion chemistry needs to be investigated in detail. Diisopropyl ketone (DIPK) is a promising biofuel candidate, which is produced using endophytic fungal conversion. A detailed understanding of the combustion kinetics of the oxidation …

Advancement And Validation Of A Plug-In Hybrid Electric Vehicle Model Utilizing Experimental Data From Vehicle Testing, Kevin Lloyd Snyder

Wayne State University Theses

The objective of the research into modeling and simulation was to provide an iterative improvement to the Wayne State EcoCAR 2 team's math-based design tools for use in evaluating different outcomes based on hybrid powertrain architecture tweaks, controls code development and testing. This thesis includes the results of the team's work in the EcoCAR 2 competition for university student teams to create and test a plug-in hybrid electric vehicle for reducing petroleum oil consumption, pollutant emissions, and Green House Gas (GHG) emissions.

Plant model validations and advancements brought the vehicle plant model directionally closer to the actual vehicle's experimental data …

Modeling Crabbing Dynamics In An Electron-Ion Collider, A. Castilla, V. S. Morozov, T. Satogata, J. R. Delayen

Physics Faculty Publications

A local crabbing scheme requires π/2 (mod π) horizontal betatron phase advances from an interaction point (IP) to the crab cavities on each side of it. However, realistic phase advances generated by sets of quadrupoles, or Final Focusing Blocks (FFB), between the crab cavities located in the expanded beam regions and the IP differ slightly from π/2. To understand the effect of crabbing on the beam dynamics in this case, a simple model of the optics of the Medium Energy Electron-Ion Collider (MEIC) including local crabbing was developed using linear matrices and then studied numerically over multiple turns (1000 passes) …

Microstructure Development Of Granular System During Compaction, Chen Shang, Marcial Gonzalez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Granular materials is the second most manipulated material in the industry today. They are easy to transport and more and more newly developed materials cannot stand the process of traditional casting, like energetic materials and bio-materials, but will survive the powder compaction process. Having a better understanding of the microstructure development of granular systems during compaction process, especially for particles that will heavily deform under loading, will give an insight of how to better process the powders to produce materials with overall better performance comparing to bulk materials. The main theory and mechanism applied are Hertz law and nonlocal contact …

Simulation Of An Intake Manifold Pre-Heater For Cold Diesel Engine Startup, Patrick K. Kreun

Masters Theses

Ensuring consistent, reliable diesel engine startups in cold temperatures is of utmost importance in a number of applications. Under extreme temperatures, the use of glow plugs is complemented by intake manifold heaters. In these, the energy released from combustion increases the intake air temperature before the air enters the main combustion chamber. Since the process also alters the stoichiometry of the fuel-air mixture at the intake ports, the preheater operation must be optimized in order to guarantee successful and reliable in-cylinder combustion during engine startups. This paper describes the development of an intake manifold model incorporating an air pre-heater for …

Thermal And Cooling Systems Modeling Of Powertrain For A Plug -In Parallel-Through-The-Road Hybrid Electric Vehicle, Mengjia Cao

Wayne State University Theses

Thermal modeling and control play an ever increasing role with hybrid electric vehicle (HEV) design and development for improving overall vehicle energy efficiency, and to account for additional thermal loading from electric powertrain components such as electric motor, motor controller and battery pack.

This thesis presents a complete development process for an efficient modeling approach with integrated control strategy for the thermal management of plug-in HEV in a parallel-through-the road (PTTR) architecture, adopted by Wayne State University Hybrid Warriors for their Department of Energy's EcoCAR2 Plugging in to the Future Competition.

The frameworks of this project include simulating the thermal …

The Effects Of Asymmetric Micro Ratchets On Pool Boiling Performance, Lance Austin Brumfield

LSU Doctoral Dissertations

Nucleate boiling is an attractive method for achieving high heat flux at low superheat temperatures. It is frequently used for industrial applications such as heat exchangers and is being considered to cool advanced central processing units (CPU) which produce heat fluxes on the order of 1 MW/m2 and are becoming increasingly less efficient to cool via forced conduction of air. The issue with implementing nucleate boiling as a cooling mechanism lies in the difficulty of quantifying the numerous and complex mechanisms which control the process. A comprehensive nucleate boiling model has yet to be formulated and will be required in …

Simulation Of Vertical Axis Wind Turbines With Variable Pitch Foils, L. Damon Woods, John F. Gardner, Kurt S. Myers

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A dynamic computer model of a turbine was developed in MATLAB in order to study the behavior of vertical axis wind turbines (VAWTs) with variable pitch (articulating) foils. The simulation results corroborated the findings of several empirical studies on VAWTs. The model was used to analyze theories of pitch articulation and to inform the discussion on turbine design. Simulations of various models showed that pitch articulation allowed Darrieus-style vertical axis wind turbines to start from rest. Once in motion, the rotor was found to accelerate rapidly to very high rotational velocities. The simulations revealed a plateau region of high efficiency …

Thin Electrical Double Layer Simulation Of Micro-Electrochemical Supercapacitors, Kaitlyn Fisher, Guoping Xiong, Timothy S. Fisher

The Summer Undergraduate Research Fellowship (SURF) Symposium

The deteriorating state of the environment has drawn many people to hybrid electric vehicles. Electrochemical micro-supercapacitors are of interest in this field because of their high power density relative to other micro-power sources. However, little is known about how the properties of the electrolyte used affect the performance of such devices. The first step of this investigation was to use thermoreflectance microscopy to measure the temperature change of the electrodes while charging and discharging supercapacitor samples. The components of these samples were graphitic petal electrodes with a Ti/Au covering (for enhanced light reflectance) on a SiO₂ base, with a …

Mems Lab Simulation Tool, Oluwatosin D. Adeosun, Sambit Palit, Ankit Jain, Muhammad A. Alam

The Summer Undergraduate Research Fellowship (SURF) Symposium

MEMS actuators have multiple design applications. Understanding their behavior as well as the ability to predict their actuation characteristics and voltage response is important when designing these actuators. In order to know these devices will behave, designers have to solve multiple analytical equations and experiments that can be very time consuming. Over the course of the summer a tool was created on nanoHUB that will allow users to enter information about a MEMS actuator and provide the voltage response of the actuator. To create the tool, scaling equations were first provided for various geometry configurations and the equations were next …