Mechanical Engineering Commons^™

A Model Of Transient Heat Transfer In A Packed Bed Of Alumina Particles, Samira Shiri

Dissertations and Theses

The present study seeks to develop a robust system-scale heat transfer model for a sensible heat storage system. A novel mechanism to simulate axial dispersion and heat loss from the boundary of the sensible heat system to the environment is introduced. The most challenging topics to develop a robust heat transfer model are related to heat loss term, selecting the more reliable method to calculate heat transfer coefficient between fluid and solid, and investigating the effect of neglecting temperature dependency of materials properties. As the storage heat system has a vertical storage vessel, the dominant heat transfer mechanism from the …

Exploring The Interaction Of Two Self-Excited Energy Harvesters, Yi Han

Dissertations and Theses

No abstract provided.

The Determination Of Drag And Lift Forces Of A Rigid Beam Located Within A Turbulent Boindary Layer By Means Of Large Eddy Simulation Modeling, Santiago Helman

Dissertations and Theses

"Recent studies such as those conducted by Akaydin, Elvin and Andreopoulos in [1] have described and quantified the electrical power that can be extracted from a moving flow by the implementation of energy harvesters. In such study, a flexible cantilevered beam was fitted with a cylindrical prism at the free end and placed within a uniform flow field. Due to the vortex shedding generated by the prism (e.g. Von Karman vortices) the beam was found to oscillate about the undisturbed position. The beam in question was then outfitted with a piezoelectric material in order to translate the transient strain energy …

Image Analysis Of Air-Bubble Injection (Front And Side View) Into A Turbulent Liquid Stream, Navjot Kaur

Dissertations and Theses

"This study concerns an air bubble injection experiments in a vertical upward annular channel in which a 0.4 mm hole was created to inject the air bubbles into the turbulent stream. Water was used as a testing fluid, and the experiments were performed at atmospheric pressure and room temperature. A high-speed video camera was used to capture the dynamics of the bubble formation process. Two different experimental views were used: a front view in which flow velocity was 0.80 m/s (2.68 GPM) at Reynolds number, Re=7413 and to inject air bubbles into water stream air bubble injection rate was set …

Modeling The Structural-Thermal-Electrical Coupling In An Electrostatically Actuated Mems Switch And Its Impact On The Switch Stability, Hassen M. Ouakad, Mohammad I. Younis

Mechanical Engineering Faculty Scholarship

Modeling and analysis for the static behavior and collapse instabilities of a MEMS cantilever switch subjected to both electrical and thermal loadings are presented. The thermal loading forces can be as a result of a huge amount of switching contact of the microswitch. The model considers the microbeam as a continuous medium and the electric force as a nonlinear function of displacement and accounts for its fringing-field effect. The electric force is assumed to be distributed over specific lengths underneath the microbeam. A boundary-value solver is used to study the collapse instability, which brings the microbeam from its unstuck configuration …

Biogeography-Based Optimization For Hydraulic Prosthetic Knee Control, Tim Wilmot, George Thomas, Berney Montavon, Rick Rarick, Antonie J. Van Den Bogert, Steve Szatmary, Daniel J. Simon, William Smith, Sergey Samorezov

Electrical and Computer Engineering Faculty Publications

We discuss open-loop control development and simulation results for a newly-developed cyber-physical system (CPS) used as a semi-active, above-knee prosthesis. The control signal of our CPS consists of two hydraulic valve settings that control a linear cylinder actuator and provide torque to the prosthetic knee. We develop open-loop control using biogeography-based optimization (BBO), which is a recently developed evolutionary algorithm. The research contributes to the field of cyber-physical systems by showing that it is possible to find effective open-loop control signals for our newly proposed semi-active hydraulic knee prosthesis through a dual-system optimization process which includes both human and robot …

Assess The Accuracy Of The Variational Asymptotic Plate And Shell Analysis Using The Generalized Uni, Luciano Demasi, Wenbin Yu

Mechanical and Aerospace Engineering Faculty Publications

The accuracy of the Variational Asymptotic Plate and Shell Analysis (VAPAS) is assessed against several higher order, zig zag and layerwise theories generated by using the invariant axiomatic framework denoted as Generalized Unified Formulation (GUF). These theories are also compared against the elasticity solution developed for the case of a sandwich structure with high Face to Core Stiffness Ratio. GUF allows to use an infinite number of axiomatic theories (Equivalent Single Layer theories with or without zig zag effects and Layerwise theories as well) with any combination of orders of the displacements and it is an ideal tool to precisely …

Dnad, A Simple Tool For Automatic Differentiation Of Fortran Codes Using Dual Numbers, Wenbin Yu, Maxwell Blair

Mechanical and Aerospace Engineering Faculty Publications

DNAD (dual number automatic differentiation) is a simple, general-purpose tool to automatically differentiate Fortran codes written in modern Fortran (F90/95/2003) or legacy codes written in previous version of the Fortran language. It implements the forward mode of automatic differentiation using the arithmetic of dual numbers and the operator overloading feature of F90/95/2003. Very minimum changes of the source codes are needed to compute the first derivatives of Fortran programs. The advantages of DNAD in comparison to other existing similar computer codes are its programming simplicity, extensibility, and computational efficiency. Specifically, DNAD is more accurate and efficient than the popular complex-step …

Thermal Conductivity Profile Determination In Proton-Irradiated Zrc By Spatial And Frequency Scanning Thermal Wave Methods, C. Jensen, M. Chirtoc, N. Horny, J. S. Antoniow, H. Pron, Heng Ban

Mechanical and Aerospace Engineering Faculty Publications

Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the …

Simulating Large Deformation Of Intraneural Ganglion Cyst Using Finite Element Method, Sachin Lokhande

Dissertations, Master's Theses and Master's Reports - Open

Intraneural Ganglion Cyst is disorder observed in the nerve injury, it is still unknown and very difficult to predict its propagation in the human body so many times it is referred as an unsolved history. The treatments for this disorder are to remove the cystic substance from the nerve by a surgery. However these treatments may result in neuropathic pain and recurrence of the cyst. The articular theory proposed by Spinner et al., (Spinner et al. 2003) considers the neurological deficit in Common Peroneal Nerve (CPN) branch of the sciatic nerve and adds that in addition to the treatment, ligation …

Influence Of Mechanical And Thermal Boundary Conditions On Stabilizing/Destabilizing Mechanisms In Evaporating Liquid Films, Aneet Dharmavaram Narendranath

Dissertations, Master's Theses and Master's Reports - Open

Liquid films, evaporating or non-evaporating, are ubiquitous in nature and technology. The dynamics of evaporating liquid films is a study applicable in several industries such as water recovery, heat exchangers, crystal growth, drug design etc. The theory describing the dynamics of liquid films crosses several fields such as engineering, mathematics, material science, biophysics and volcanology to name a few.

Interfacial instabilities typically manifest by the undulation of an interface from a presumed flat state or by the onset of a secondary flow state from a primary quiescent state or both. To study the instabilities affecting liquid films, an evaporating/non-evaporating Newtonian …

Development Of The Ecocar 3 Proposal And Guidelines For Modeling And Design In Year One Of Ecocar 3, Tyler B. Daavettila

Dissertations, Master's Theses and Master's Reports - Open

This report summarizes the work done for the Vehicle Powertrain Modeling and Design Problem Proposal portion of the EcoCAR3 proposal as specified in the Request for Proposal from Argonne National Laboratory.

The results of the modeling exercises presented in the proposal showed that:

• An average conventional vehicle powered by a combustion engine could not meet the energy consumption target when the engine was sized to meet the acceleration target, due the relatively low thermal efficiency of the spark ignition engine.
  

• A battery electric vehicle could not meet the required range target of 320 km while keeping the vehicle weight below …

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Lattice Boltzmann Method And Cellular Automata Simulation Of Particle Motion And Deposition In 2-D Case, Yichao Deng

Dissertations, Master's Theses and Master's Reports - Open

This technical report discusses the application of the Lattice Boltzmann Method (LBM) and Cellular Automata (CA) simulation in fluid flow and particle deposition. The current work focuses on incompressible flow simulation passing cylinders, in which we incorporate the LBM D2Q9 and CA techniques to simulate the fluid flow and particle loading respectively. For the LBM part, the theories of boundary conditions are studied and verified using the Poiseuille flow test. For the CA part, several models regarding simulation of particles are explained. And a new Digital Differential Analyzer (DDA) algorithm is introduced to simulate particle motion in the Boolean model. …

Processing Of Continuous Fiber Reinforced Ceramic Composites For Ultra High Temperature Applications Using Organosilicon Polymer Precursors, James Robert Nicholas

Masters Theses

"The current work is on the development of continuous fiber reinforced ceramic materials (CFCCs) for use in ultra high temperature applications. These applications subject materials to extremely high temperatures (> 2000⁰C). Monolithic ceramics are currently being used for these applications, but the tendency to fail catastrophically has driven the need for the next generation of material. Reinforcing with continuous fibers significantly improves the toughness of the monolithic materials; however, this is a manufacturing challenge. The development of commercial, low-viscosity preceramic polymers provides new opportunities to fabricate CFCCs. Preceramic polymers behave as polymers at low temperatures and are transformed into ceramics …

Parameter Optimization For Controlling Aluminum Loss When Laser Depositing Ti-6al-4v, Richard Charles Barclay

Masters Theses

"The ability to predict the mechanical properties of engineering materials is crucial to the manufacturing of advanced products. In the aerospace industry, Ti-6Al-4V is commonly used to build structures. Any deviation from the alloy's standard properties can prove detrimental. Thus, the compositional integrity of the material must be controlled. The ability to directly build and repair large, complicated structures directly from CAD files is highly sought after. Laser Metal Deposition (LMD) technology has the potential to deliver that ability. Before this process can gain widespread acceptance, however, a set of process parameters must be established that yield finished parts of …

A Novel Resistance Exercise Machine For Use In A Lower Body Negative Pressure Box To Counteract The Effects Of Weightlessness, Christine M. Dailey

Doctoral Dissertations and Master's Theses

Physiological deconditioning is a critical problem in space, especially during long-term missions. Resistance exercise coupled with lower body negative pressure (LBNP) has been shown to be effective in counteracting some of the deconditioning related problems. This thesis describes the development of a compact and effective resistance exercise machine that works within an existing environmentally controlled LBNP Box and is designed to simulate both exercise and sitting, to prevent microgravity-induced deconditioning by simulating physiological and biomechanical features of upright exercise and daily activities. Theoretical calculations are carried out to determine whether kinematics, musculoskeletal loadings, and metabolic rate during supine exercise within …

Development Of `Lick And Stick' Passive Wireless Temperature Sensor For Harsh Environment, Hasanul Karim

Open Access Theses & Dissertations

Wireless passive temperature sensors have been receiving increasing attention due to the ever-growing need of higher energy efficient and precise monitoring of temperatures in high temperature energy conversion systems such as gas turbines and coal-based power plants. Unfortunately, the harsh environment such as high temperature and corrosive atmosphere present in these systems has significantly limited the reliability and increased the cost of current solutions. Therefore, this research project presents the concept and design of a low cost, passive, and wireless temperature sensor that can withstand high temperature and harsh environment. The temperature sensor was designed following the principle of metamaterials …

A Damage-Trap Interfacial Design To Improve Impact Resistance Of Polymers, Md Shariful Islam

Open Access Theses & Dissertations

Polymer materials such as Polycarbonate (PC), Polymethyl methacrylate (PMMA) have numerous applications in transparent armor which includes body and face shield, helmet, windows of the armored vehicle etc. The most challenging part of these applications is to ensure the safety of the people. These materials are often subjected to impact loading, so it is important to study the failure of these materials under impact loading. An experimental study has been made to investigate the impact damage in transparent layered materials. Impact experiments were carried out on various monolithic specimens and layered specimens for both two types of materials at different …

Investigation Of The Radiative Heat Release Factor Of Premixed Oxy-Syngas Flames, Martin De La Torre

Open Access Theses & Dissertations

A significant part of the United States is being powered by combustion devises relying on coal since it is abundant and is a high emitting source of electricity per unit energy, however; the burning of this fuel is responsible for a significant contribution for the pollutant emissions causing global warming. Because coal is one of the main sources of energy in the U.S. and around the globe, the scientific community has been investigating ways to meet current and future governmental emission requirements. It is now well established that radiating heat from the flame is a major contributor of the heat …

Pressure And Heat Flux Effects On The Heat Transfer Characteristics Of Liquid Methane, Chance Paul Garcia

Open Access Theses & Dissertations

The heat transfer effects on liquid methane are investigated with the use of a carbo-thermal rig at the Center for Space Exploration Technology Research (cSETR) located at the University of Texas at El Paso (UTEP). The cSETR carbo-thermal rig design approach is presented along with the design of a methane condensing mobile unit (MCMU) to supply the laboratory and rig with liquid methane. The proposed research will generate useful insight in to heat transfer coefficient behavior, non-dimensional correlations, different flow conditions, varied inlet conditions, and varied heat flux for a subscale test article applicable to a regenerative cooled rocket engine …

Process Study And Control Of Electron Beam Melting Technology Using Infrared Thermography, Jorge Mireles

Open Access Theses & Dissertations

An IR camera was installed in an Arcam A2 system (Arcam AB, Mölndal, Sweeden) and layer-by-layer image acquisition was achieved. The camera's capability to detect manufacturing defects was evaluated by implementing computer vision techniques using LabVIEW measurement and programming software (National Instruments, Austin, TX). Thermal maps acquired by the IR camera allowed layer-by-layer part temperature to be recorded. A core objective of this research was to study the impact of processing temperature on EBM-fabricated Ti-6Al-4V parts and achieve controlled mechanical properties. In this research, build variations were achieved by modifying parameters that change processing temperature from the standard processing temperature. …

The Development Of Self-Supported Electromechanical Structures Using Fused Deposition Modeling, Jorge Ramos-Almeida

Open Access Theses & Dissertations

Recent research has focused on the fabrication freedom of 3D printing to create not only conceptual models but also final end-use products. In the last decade, several research groups have reported embedding electronic components and electrical interconnects into 3D printed structures during process interruptions; however, to date there is an absence of fabricated devices with electromechanical functionality for parts fabricated in a single Additive Manufacturing (AM) build sequence.

The focus of this research is the use of Fused Deposition Modeling (FDM) to manufacture a self-supported electromechanical motor. FDM is an AM process capable of building parts in a layer-by-layer fashion. …

Inkjet Based Personalized Screening Platform For Cancer Therapy, Jorge Ivan Rodriguez

Open Access Theses & Dissertations

The new paradigm of personalized medicine is beginning to affect clinical practice. In particular, many of the advances in genomics and proteomics have made personalized screening and therapeutic inventions possible. On chip, cellomics approaches to screening and intervention are becoming more commonplace. Cancer therapies may benefit from the rise in `-omics' technologies. In addition, the availability of rapid screening data is crucial to mitigate cancer propagation and increase the possibility of patient recovery. This study is an endeavor to develop a cellomic anticancer drug screening process based on inkjet printing. Previous research has demonstrated that inkjet based screening can reliably …

Molecular Dynamics Simulation Studies Of Interaction Of Amphiphilic Molecules With Lipid Bilayers, Jieqiong Lin

LSU Doctoral Dissertations

We use molecular dynamics simulations to investigate the behavior of various amphiphilic molecules in aqueous solutions in the presence of vitamin E or lipid bilayers. Our research studies focus on two molecular systems. First, we investigate the effect of DMSO on structural properties of DMPC bilayers and calculate bilayers permeability coefficients for both water and DMSO molecules at low DMSO concentration. The simulations show that the increase of DMSO concentration in solution leads to an increase of the permeability of water through the bilayers. The permeability increase might explain the unusual ability of DMSO, even at relatively low concentrations, to …

A Fluorescent Oil Detection Device, Yuxuan Zhou

LSU Doctoral Dissertations

On April 20th 2010, the largest offshore oil spill in U.S. history happened in the Gulf of Mexico. It is estimated total more than 4 million barrels oil spilled to Gulf of Mexico. More than two million gallons had been used. This had made the threat to coastal and sea ecosystem even greater and long term. Real-time monitoring is also a critical topic for oil spill response. In-situ monitoring devices are needed for rapid collection of real-time data. A new generation of instruments for spilled oil detection is reported in this paper. The main hypothesis in this research is that …

Measurement Of Continuum Breakdown Using A Disc Spin-Down Experiment In Low Pressure Air, Tathagata Acharya

LSU Doctoral Dissertations

As flow becomes rarefied, a quantity called as the tangential momentum accommodation coefficient (TMAC) becomes important because it is a measure of the momentum transport from a gas molecule to a surface. Very few experimental measurements of continuum breakdown in boundary layer flows exist. All experimental measurements of the TMAC in macro-scale boundary layer flows have been done in the continuum slip and the transition flow regimes. Moreover the experimental apparatus used by previous researchers cannot accommodate for materials that are planar by nature such as those used in the field of aerospace and microfabrication. The objectives of this research …

Large Eddy Simulation And Analysis Of Shear Flows In Complex Geometries, Prasad Mohanrao Kalghatgi

LSU Doctoral Dissertations

In the present work, large eddy simulation is used to numerically investigate two types of shear flows in complex geometries, (i) a novel momentum driven countercurrent shear flow in dump geometry and (ii) a film cooling flow (inclined jet in crossflow). Verification of subgrid scale model is done through comparisons with measurements for a turbulent flow over back step, present cases of counter current shear and film cooling flow. In the first part, a three dimensional stability analysis is conducted for countercurrent shear flow using Dynamic mode decomposition and spectral analysis. Kelvin-Helmholtz is identified as primary instability mechanism and observed …

Modification Of Luas Heating And Ventilation Systems To Reduce Energy Consumption, Eogan Sweeney, James Brunton

Conference Papers

Luas is a state of the art light rail system operating in Dublin Ireland. Being electrically powered, energy is a major operating cost for Luas. One component of rolling stock identified by this research that consumes a disproportional amount of energy is that of the heating and ventilation systems. The heating and ventilation systems fitted to Luas vehicles consume as much as 60% of total vehicle power, and under certain conditions can consume more than that of the traction motors. This paper explores solutions to reducing the energy consumption of Luas heating and ventilation systems. The identified software modifications and …

Mechanics Of Hip Dysplasia Reduction In Infants Using The Pavlik Harness: A Physics Based Computational Model, Orlando Ardila, Eduardo Divo, Faissal Moslehy, George Rab, Alain Kassab, Charles Price

Mechanical Engineering - Daytona Beach

Biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of Developmental Dysplasia of the Hip (DDH) were studied using a three-dimensional computer model simulating hip reduction dynamics in (1) subluxated and (2) fully dislocated hip joints. Five hip adductor muscles were identified as key mediators of DDH prognosis, and the non-dimensional force contribution of each in the direction necessary to achieve concentric hip reductions was determined. Results point to the adductor muscles as mediators of subluxated hip reductions, as their mechanical action is a function of the degree of hip dislocation. For subluxated hips in …

Project Haiti 2012: Providing An Experiential Learning Experience Through The Design And Delivery Of A Water Purifier In Haiti, Yung Wong, Johnathon Camp, Shavin Pinto, Kyle Fennesy, Marc Compere, Yan Tang

Publications

In this paper, we share our experiences and lessons learned from Project Haiti 2012, a project to design and install a water purification system serving 20,000 people per day in the largest tent city in Haiti. Project Haiti 2012 was the third and largest system we have built for Haitians and represents a huge success for all participants and stakeholders. This paper discusses the unique experiential learning opportunity involved in the design and delivery of the water purifier in a foreign developing country. Multiple positive educational, social, and economic outcomes were achieved including students applying knowledge gained from coursework towards …