Mechanical Engineering Commons^™

Manufacturing And Characterization Of Energetic Materials, Carlos Alberto Catzin

Open Access Theses & Dissertations

Few products take several years of research effort to be synthesize yet disintegrate in scarcely millionths of a second when used. Despite their short lifespan energetic materials, particularly high explosives, are in demand as never before by the Aerospace, Defense, Energy, Gas, Mining, and Oil Industry for their unique properties. One class of high explosives known as polymer bonded explosives (PBXs) are popularly used in a wide variety of applications ranging from solid rocket propellants to the main explosive charge in conventional ammunitions. A key characteristic behind the popularity of PBXs in comparison to other high explosives is their handling …

Combustion Of Novel Thermite Mixtures For Iodine Generation, Sergio Emanuel Guerrero

Open Access Theses & Dissertations

Halogen-containing reactive materials could be used for mitigating the spread of hazardous, active biological microorganisms aerosolized as a result of explosion. The present work exhibits experimental results on the combustion of mechanically alloyed aluminum-iodine (Al-I2) powder mixed with Fe2O3, CuO, MoO3, Bi2O3, and I2O5. Wet mixing was used to prepare the samples, which were then compacted into pellets and ignited with a CO2 laser. A chamber was designed and built to accommodate for combustion and collection of products, and the available laser ignition setup was modified to enable combustion experiments with rapidly burning gas-generating mixtures. High-speed video recording was used …

Analysis Of Road Vehicle Aerodynamics With Computational Fluid Dynamics, Christian Armando Mata

Open Access Theses & Dissertations

A road vehicles aerodynamics can be one of the most influential aspects of its performance. With the increased importance on fuel efficiency in recent years, new road vehicles are being developed smaller in size, with smaller displacement engines, as well as with improved aerodynamics. The aerodynamics of a vehicle can have a significant effect on its fuel efficiency, as well as other important aspects of the vehicles performance such as the top speed, acceleration, and handling. A study focusing on analyzing aerodynamic effects due to vehicle geometries such as wheels covered by the vehicles body in comparison to open wheels …

Modeling Of Piezoelectric Traveling Wave Rotary Ultrasonic Motors With The Finite Volume Method, Ivan Arturo Renteria Marquez

Open Access Theses & Dissertations

In 1983 Toshiiku Sashida developed a new motor concept called Piezoelectric Traveling Wave Rotary Ultrasonic Motor (PTRUSM). The advantages of these motors include high torque at low speed, absence of a generated magnetic field, and high potential for miniaturization. Unfortunately PTRUSMs have some disadvantages that limit the areas of applications for these types of motors. The disadvantages are a short operating life (about 1000 hours), small output power, and the need of a complex motor controller.

On one hand, these motors have been used in satellites, mobile phones, photocopiers, robotic arms, telescopes, automobiles, and camera autofocusing. On the other hand, …

Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana

Open Access Theses & Dissertations

ANSYS Fluent was used to optimize components of a direct power extraction combustor. This includes the fuel injector, nozzle, and cooling units. Changes in the injector's inlet location impacted pressure and velocity distribution. An angle of 115 degrees with respect to the x-axis was found to increase distribution efficiency. Temperature and velocity data from the combustor and nozzle were calculated using NASA CEA and Fluent. Magnitudes of temperature and velocity for CEA and Fluent matched within 9% and 4%, respectively. For the cooling system it is expected that cavitation will not occur since the saturation temperature of water is not …

Period Batch Control - A Production Planning System Applied To Virtual Manufacturing Cells, Z. Tesic, B. Stevanaov, V. Jovanovic, M. Tomic, C. Kafol

Engineering Technology Faculty Publications

Period Batch Control (PBC) system has been known for its implementation with the classical group technology (GT) cells, and it has been known for its simplicity. The main production planning decisions concern the choice of the period length and the stage number and contents. Also, in order to better integrate the production planning with the application of GT cells at the shop floor, the concept of virtual manufacturing cells has been applied. Since virtual cells configurations are changing periodically, a model for implementing the PBC system into virtual manufacturing cells environment is developed. The model enables alignment of the PBC …

A Pilot Program For The Recruitment And Education Of Navy Veterans Based On System-Level Technical Expertise And Leadership Maturation Developed During Service, Anthony W. Dean, Connor Schwalm, Patrick S. Heaney, Linda Vahala, Yuzhong Shen, Jennifer G. Michaeli

Engineering Technology Faculty Publications

The project, Stern2STEM, aims to advance STEM (Science, Technology, Engineering, and Mathematics) education through the preparation of student veterans to pursue baccalaureate STEM degrees and support the re-employment of these veterans into the Department of Defense (DoD) and the wider defense support industry. The program builds on the training that veterans have received in highly skilled technical areas, both in the classroom and “on-the-job”, to develop system level expertise in their respective technical disciplines. Key components of the program include: (1) establishing a mechanism for outreach and recruitment; (2) providing leveling, tutoring, mentoring, and support for students; (3) teaching …

Regression Analysis Of Pem Fuel Cell Transient Response, Russell L. Edwards, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

To develop operating strategies in polymer electrolyte membrane (PEM) fuel cell-powered applications, precise computationally efficient models of the fuel cell stack voltage are required. Models are needed for all operating conditions, including transients. In this work, transient evolutions of voltage, in response to load changes, are modeled with a sum of three exponential decay functions. Amplitude factors are correlated to steady-state operating data (temperature, humidity, average current, resistance, and voltage). The obtained time constants reflect known processes of the membrane heat/water transport. These model parameters can form the basis for the prediction of voltage overshoot/undershoot used in computational-based control systems, …

Electrokinetic Phenomena In Pencil Lead-Based Microfluidics, Yashar Bashirzadeh, Venkat Maruthamuthu, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

Fabrication of microchannels and associated electrodes to generate electrokinetic phenomena often involves costly materials and considerable effort. In this study, we used graphite pencil-leads as low cost, disposable 3D electrodes to investigate various electrokinetic phenomena in straight cylindrical microchannels, which were themselves fabricated by using a graphite rod as the microchannel mold. Individual pencil-leads were employed as the micro-electrodes arranged along the side walls of the microchannel. Efficient electrokinetic phenomena provided by the 3D electrodes, including alternating current electroosmosis (ACEO), induced-charge electroosmosis (ICEO), and dielectrophoresis (DEP), were demonstrated by the introduced pencil-lead based microfluidic devices. The electrokinetic phenomena were characterized …

Thermophysical And Thermochemical Property Measurement And Prediction Of Liquid Metal Titanium Alloys With Applications In Additive Manufacturing, Jonathan Richard Raush

LSU Doctoral Dissertations

Accurate high-temperature thermophysical property data for liquid metals and alloys are important for simulation of laser-based 3D printing processes. To understand and better control such additive manufacturing processes, knowledge of density, viscosity, and surface tension of liquid metals and alloys versus composition and temperature is needed. Likewise, thermochemical property data information regarding alloys, including chemical activities and free energies relative to composition and temperature, aid in the understanding and development of phase data important in the material design process. Vacuum electrostatic levitation (ESL) is an important technique through which both thermophysical and thermochemical property measurements can be accomplished without physical …

Optimal Configuration Of Inspection And Rework Stations In A Multistage Flexible Flowline, Md. Shahriar Jahan Hossain

LSU Master's Theses

Inspection and rework are two important issues of quality control. In this research, an N-stage flowline is considered to make decisions on these two issues. When defective items are detected at the inspection station the items are either scrapped or reworked. A reworkable item may be repaired at the regular defect-creating workstation or at a dedicated off-line rework station. Two problems (end-of-line and multistage inspections) are considered here to deal with this situation. The end-of-line inspection (ELI) problem considers an inspection station located at the end of the line while the multistage inspection (MSI) problem deals with multiple in-line inspection …

The Design, Fabrication, And Validation Of A Film Cooled Rotating Turbine Cascade With An Actively Cooled Shroud In A Closed Loop Wind Tunnel, Christopher Michael Drewes

LSU Master's Theses

To test shroud and blade cooling effectiveness, a closed loop, heated wind tunnel housing a film cooled rotating turbine cascade with prescribed blade and vane geometry surrounded by a fully cooled shroud with a leading edge gap were designed and assembled on Louisiana State University’s campus. Heat transfer coefficients and film cooling effectiveness results were computed using a 1-D semi-infinite solid conduction analysis of material temperatures obtained with liquid crystal thermography. Proper analysis required a step change in air temperature; so a bypass loop provided mainstream air heating while maintaining the shroud and blades at ambient temperature. Also, analysis required …

Characterization Of Thermoplastic Fusion Bonding Of Microchannels Using Pressure Assisted Boiling Point Control System, Kavya Dathathreya

LSU Master's Theses

An innovative method of thermoplastic fusion bonding using a pressure assisted boiling point control (PABP) system was characterized to determine the optimum parameters for bonding polymethyl methacrylate (PMMA) components containing microchannels and thin, 250 µm cover sheets. The PABP system enables precise control of the temperature boundary condition and the applied pressure by immersing the components being bonded in boiling water and varying the vapor pressure. Test structure geometries containing microchannels of two depths and four different aspect ratios were designed: 1:10 (Depth: 10µm, Width: 100 µm and Depth: 5µm, Width: 50 µm), 1:50 (Depth: 10µm, Width: 500µm and Depth: …

Weld Quality Classification From Sensory Signatures In Friction-Stir-Welding (Fsw) Using Discrete Wavelet Transform And Advanced Metaheuristic Techniques, James Devecmon Roberts

LSU Master's Theses

Controlling the quality of welds is an essential part of high quality fabrications and ensuring structural integrity of welded joints and welded structures. Industry is in an endless pursuit to find more cost effective methods of testing welds for defects and eliminating them entirely. This Study contributes to this goal by investigating a new system with the ability to monitor welding conditions during the forging process. Monitoring the condition of the weld, while the metals are joined together is faster and more cost- effective than conventional methods of post-weld defect detection. In this study, the feedback signals are first collected …

Photonic Microstructures For Energy-Generating Clear Glass And Net-Zero Energy Buildings, Mikhail Vasiliev, Ramzy Alghamedi, Mohammad Alam, Kamal Alameh

Research outputs 2014 to 2021

Transparent energy-harvesting windows are emerging as practical building-integrated photovoltaics (BIPV), capable of generating electricity while simultaneously reducing heating and cooling demands. By incorporating spectrally-selective diffraction gratings as light deflecting structures of high visible transparency into lamination interlayers and using improved spectrally-selective thin-film coatings, most of the visible solar radiation can be transmitted through the glass windows with minimum attenuation. At the same time, the ultraviolet (UV) and a part of incident solar infrared (IR) radiation energy are converted and/or deflected geometrically towards the panel edge for collection by CuInSe₂ solar cells. Experimental results show power conversion efficiencies in excess …

Mechanical Characterization Of Sicf-Sicm Nuclear Fuel Cladding By A Novel Hydraulic Internal Pressurization Method, Kirill Shapovalov

Theses and Dissertations

Ceramic Matrix Composites (CMC) have been actively researched for applications requiring high temperature strength and damage tolerance. Examples are turbine engine hot section components, leading edges for hypersonic vehicles, nuclear fusion reactor first wall and blanket, and recently nuclear fuel claddings. Predictable material damage behavior is desirable for these applications so early damage accumulation can be detected before a catastrophic failure occurs. Many ceramic materials can withstand high temperature environments, but due to inherent brittleness of ceramics the high damage tolerance and the predictable damage behavior are difficult to achieve. Ceramic fiber reinforced ceramic composites (CFCC) have demonstrated the above …

Physics Based Modeling Of Guided Waves For Detection And Characterization Of Structural Damage In Nde And Shm, Banibrata Poddar

Theses and Dissertations

Guided waves based damage detection techniques are popular for their ease of generation and detection along with their ability to travel long distances. Accurate and efficient modeling is a key for successful implementation of guided waves for NDE/SHM. However, efficient prediction of scattering from various damage is challenging due to the complex nature of these guided waves.

This dissertation presents as physics based efficient and accurate modeling techniques to predict ultrasonic wave propagation and their interaction with various damage. Detection and characterization of damage in structures can typically be divided into two categories, active and passive. This research is aimed …

Detection Of Periodic Error And Structure Change Using Wavelet Analysis, Chao Lu

Theses and Dissertations

Heterodyne displacement measuring interferometry provides important metrology for applications requiring high resolution and accuracy. Heterodyne Michelson interferometers use a two-frequency laser source and separate the two optical frequencies into one fixed length and one variable length path via polarization. Ideally these two beams are linearly polarized and orthogonal so that only one frequency is directed toward each path. An interference signal is obtained by recombining the light from the two paths; this results in a measurement signal at the heterodyne (split) frequency of the laser source. This measurement signal is compared to the optical reference signal. Motion in the measurement …

Ndt And Shm Methods Of Damage Detection In Welded Structures, Saad Mohammed

Theses and Dissertations

There has been an increasing demand for Nondestructive Testing (NDT) and Structural Health Monitoring (SHM) techniques to continuously monitor during all processes of a structure to prevent catastrophic failure and reduce maintenance costs. NDT and SHM are inspection processes which form part of the quality assurance/quality control (QA/QC) scheme. Among NDT and SHM methods, ultrasonic and guided wave techniques are the most commonly and widely used in industry. Ultrasonic methods provide the advantage of accurately locating and dimensioning defects within structures. Most of these structures consist of welded joints because welding is an economical and efficient method for obtaining a …

Friction Stir Welding And Processing On Titanium Alloys, Dawei Li

Theses and Dissertations

Friction stir welding (FSW) is a solid-state joining process that utilizes a non-consumable, rotating tool to plunge into abutting faces and transverse along the weld path. Material nearby the tool is softened by frictional heat generated via local friction and plastic deformation. Severe plastic deformation of the interface along with a state of hydrostatic pressure results in creation of a joint by metallurgical bonding. Because the temperature of the material during the welding process is below that of the melting point, FSW has numerous advantages over conventional fusion welding. Friction consolidation (FC) is also a solid-state process that uses a …

Statistical Modeling To Investigate Anatomy And Function Of The Knee, Lowell Matthew Smoger

Electronic Theses and Dissertations

The natural knee is a hinge joint with significant functional requirements during activities of daily living; as a result, acute and chronic injuries can occur. Pathologies are influenced by joint anatomy and may include patellar maltracking, cartilage degeneration (e.g. osteoarthritis), or acute injuries such as meniscal or ligamentous tears. Population variability makes broadly applicable conclusions about etiology of these conditions from small-scale investigations challenging. The work presented in this dissertation is a demonstration of statistical modeling approaches to evaluate population variability in anatomy of the knee and function of its tibiofemoral (TF) and patellofemoral (PF) joints. Three-dimensional (3D) computational models …

Implications Of Electric Vehicles On Gasoline Tax Revenues, Florida Solar Energy Center, Kevin Schleith

FSEC Energy Research Center®

This report summarizes the results of research conducted to determine if current and near future EV sales will have an impact on gasoline (gas) tax revenues as part of the Federal Highway Trust Fund (HTF). Gasoline taxes account for $31.1 billion or about 87% of the HTF. The project results were accomplished through a review of existing industry and government reports that detail fuel tax revenues and through analysis of EV sales from 2010 to 2015.

Direct Numerical Simulation Of Cylindrical Particle-Laden Gravity Currents, ‪Nadim Zgheib, Thomas Bonometti, S. Balachandar

Mechanical Engineering Faculty Publications

We present results from direct numerical simulations (DNS) of cylindrical particle-laden gravity currents. We consider the case of a full depth release with monodisperse particles at a dilute concentration where particle–particle interactions may be neglected. The disperse phase is treated as a continuum and a two-fluid formulation is adopted. We present results from two simulations at Reynolds numbers of 3450 and 10,000. Our results are in good agreement with previously reported experiments and theoretical models. At early times in the simulations, we observe a set of rolled up vortices that advance at varying speeds. These Kelvin–Helmholtz (K–H) vortex tubes are …

Analysis Of Capillary Flow In Interior Corners : Perturbed Power Law Similarity Solutions, Joshua Thomas Mccraney

Dissertations and Theses

The design of fluid management systems requires accurate models for fluid transport. In the low gravity environment of space, gravity no longer dominates fluid displacement; instead capillary forces often govern flow. This thesis considers the redistribution of fluid along an interior corner. Following a rapid reduction of gravity, fluid advances along the corner measured by the column length z = L(t), which is governed by a nonlinear partial differential equation with dynamical boundary conditions. Three flow types are examined: capillary rise, spreading drop, and tapered corner. The spreading drop regime is shown to exhibit column length growth L ~ …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Georgia Southern Research Focus Prompts R2 Carnegie Designation

2015 Fall Engr333 Project Final Report, Zach Carney, Vicent Rovedatti, Caleb Meindertsma, Daniel Devries, Tobin Tarantowski, Hanfei Niu, Kemal Talen, Ayo Ayoola, Dalton Veurink, Mitch Dubois, Jacob Milhorn, Joseph Cha, Andrew Bouma, Lance Jensen, Se Ge Jung, J. Alex Karr, Stephen Lander, Justin Cooper, Zach Veenstra, Ross Tenney, Phil Van Strien

ENGR 333

The ENGR-333 class was tasked with answering the question: “What would it take for Calvin College to save $600,000/year on campus operations?” The class choose five buildings as study samples, and invested the saving potential on three aspects: energy efficiency, operational and behavioral changes. The five buildings chose by the class were the: Covenant Fine Arts Center, Kalsbeek Huizinga vanReken, Science Building Complex, Shultze Eldersveld, and Spoelhof Fieldhouse Complex.

Turning An Organic Semiconductor Into A Low-Resistance Material By Ion Implantation, Beatrice Fraboni, Alessandra Scidà, Piero Cosseddu, Yongqiang Wang, Michael Nastasi, Silvia Milita, Annalisa Bonfiglio

Nebraska Center for Energy Sciences Research: Publications

We report on the effects of low energy ion implantation on thin films of pentacene, carried out to investigate the efficacy of this process in the fabrication of organic electronic devices. Two different ions, Ne and N, have been implanted and compared, to assess the effects of different reactivity within the hydrocarbon matrix. Strong modification of the electrical conductivity, stable in time, is observed following ion implantation. This effect is significantly larger for N implants (up to six orders of magnitude), which are shown to introduce stable charged species within the hydrocarbon matrix, not only damage as is the case …

Developing And Testing An Anguilliform Robot Swimming With Theoretically High Hydrodynamic Efficiency, John B. Potts Iii

LSU New Orleans Theses and Dissertations

An anguilliform swimming robot replicating an idealized motion is a complex marine vehicle necessitating both a theoretical and experimental analysis to completely understand its propulsion characteristics. The ideal anguilliform motion within is theorized to produce ``wakeless'' swimming (Vorus, 2011), a reactive swimming technique that produces thrust by accelerations of the added mass in the vicinity of the body. The net circulation for the unsteady motion is theorized to be eliminated.

The robot was designed to replicate the desired, theoretical motion by applying control theory methods. Independent joint control was used due to hardware limitations. The fluid velocity vectors in the …

Electromechanics Of An Ocean Current Turbine, Vasileios Tzelepis

LSU New Orleans Theses and Dissertations

The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 …

A General-Purpose Multiphase/Multispecies Model To Predict The Spread, Percutaneous Hazard, And Contact Dynamics For Nonporous And Porous Substrates And Membranes, Homayun K. Navaz, Ali R. Zand, Amir Gat, Theresa S. Atkinson

Mechanical Engineering Publications

A computational model to solve the coupled transport equations with chemical reaction and phase change for a liquid sessile droplet or the contact and spread of a sessile droplet between two approaching porous or non-porous surfaces, is developed. The model is general therefore it can be applied to toxic chemicals (contact hazard), drug delivery through porous organs and membranes, combustion processes within porous material, and liquid movements in the ground. The equation of motion and the spread of the incompressible liquid available on the primary surface for transfer into the contacting surface while reacting with other chemicals (or water) and/or …