Mechanical Engineering Commons^™

Performance Evaluation Of A Lox-Lch4 Reaction Control System Thruster, Jose Luis Mena

Open Access Theses & Dissertations

The following work outlines the assessment and characterization of a 2 to 8 lbf LOX - LCH4 reaction control thruster. The evaluation includes both experimental tests and preliminary computational analysis. Testing was conducted at O/F values ranging from 1.0 to 3.0; however, future testing will evaluate the thruster at higher and intermediate mixture ratios. The test setup includes three main systems: cryogenic propellant delivery system, thrust measurement capability, and automation and controls system. Propellant flow control is achieved through the use of in-house designed cavitating venturis. Autonomous system control is accomplished via a LabVIEW program interface and DAQ system. This …

Fabrication Of A Nickel-Based Superalloy In Electron Beam Melting And Process Improvements Using Thermal Feedback From A Multi-Wavelength Pyrometer, Jonathan Minjares

Open Access Theses & Dissertations

The focus of this research was to fabricate parts composed of a nickel-based superalloy containing high levels of aluminum and titanium (NSAT) by using electron beam melting (EBM) additive manufacturing (AM) technology and utilizing thermal feedback from a multi-wavelength pyrometer to perform process improvements leading to near defect-free parts. EBM is an AM technology that utilizes metal powder to fabricate parts in layer-by-layer manner. A multi-wavelength pyrometer was implemented in an Arcam S12 (Arcam AB, Sweden) EBM system to observe and record surface temperatures throughout fabrication. Temperature data from the EBM system and the multi-wavelength pyrometer were graphed using MATLAB …

Design And Evaluation Of A High Temperature/Pressure Supercritical Carbon Dioxide Direct Tubular Receiver For Concentrating Solar Power Applications, Jesus Daniel Ortega

Open Access Theses & Dissertations

This work focuses on the development of a solar power thermal receiver for a supercritical-carbon dioxide (sCO2), Brayton power-cycle to produce ~1 MWe. Closed-loop sCO2 Brayton cycles are being evaluated in combination with concentrating solar power to provide higher thermal-to-electric conversion efficiencies relative to conventional steam Rankine cycles. High temperatures (923 - 973 K) and pressures (20 - 25 MPa) are required in the solar receiver to achieve thermal efficiencies of ~50%, making concentrating solar power (CSP) technologies a competitive alternative to current power generation methods. In this study, the CSP receiver is required to achieve an outlet temperature of …

Synthesis, Microstructure And Performance Evaluation Of Gadolinium Incorporated Cobalt Ferrite Ceramics, Md Taibur Rahman

Open Access Theses & Dissertations

Spinel structured ferrites exhibit remarkable properties and phenomena, which are attractive for application in sensors and actuators, magneto-electronics, and electrochemical energy storage devices. Among spinel ferrites, cobalt ferrite CoFe₂O₄ (CFO) has attracted remarkable attention and widely studied because of their electro-magnetic properties, chemical stability and mechanical hardness. The properties and phenomena of CFO ceramics are dependent on microstructure and chemistry, which in turn depend on the synThesis processes and conditions employed for fabrication. Generally exact chemical composition, processing temperature, reactive or processing atmosphere (if any) and the ions that substitute Fe³⁺/Fe²⁺ ions dictate the …

Design And Development Of Implantable And Remote Controlled Distraction Osteogenesis Device For Limb Lengthening Practice In Children, Mario Eduardo Rodriguez De La O

Open Access Theses & Dissertations

Recent technology improvements have been positively affecting medical industry in recent years since procedures and equipment are more precise and reliable. Nevertheless, there are still surgical procedures and medical devices that not fully address specific needs according to medical experts. One of those necessities is focused on options available for children patients when subjected to a surgical procedure named distraction osteogenesis. In general, distraction osteogenesis is performed when skeletal deformities need to be corrected or when bone lengthening is required, typically a mechanism is utilized to elongate bone at a controlled rate. The existing osteodistraction methods for limb lengthening and …

An Experimental Investigation On Liquid Methane Convection And Boiling In Rocket Engine Cooling Channels, Abraham Trujillo

Open Access Theses & Dissertations

In the past decades, interest in developing hydrocarbon-fueled rocket engines for deep spaceflight missions has continued to grow. In particular, liquid methane (LCH4) has been of interest due to the weight efficiency, storage, and handling advantages it offers over several currently used propellants. Deep space exploration requires reusable, long life rocket engines. Due to the high temperatures reached during combustion, the life of an engine is significantly impacted by the cooling system's efficiency. Regenerative (regen) cooling is presented as a viable alternative to common cooling methods such as film and dump cooling since it provides improved engine efficiency. Due to …

The Interfacial Fracture Of Bonded Materials And Composites, Kai Zhao

Open Access Theses & Dissertations

Adhesive bonding and composite materials have been widely used in manufacturing industry. Failure results from the weakest link in a structure and this is often the interface between two materials. In case of composites, it becomes the fiber and matrix interface. In case of bonded polymers, the bonding line is the interface. This Dissertation is focused on the interfacial fracture of bonded materials and composites. First, a systematic experimental investigation on adhesive bonding strengths of polymer/polymer and polymer/metal joints was conducted and the experimental results were compared with other researchers' work. Then, a modified short-beam shear approach is developed to …

Development Of A Variable Stiffness Locally Adjustable And Repairable Low-Cost Energy Storage And Return Carbon Fiber Prosthetic Foot: A Feasibility Study, Joshua Scott Bowen

Open Access Theses & Dissertations

Background: Energy storage and return (ESAR) prosthetic feet were developed to improve the mobility and function of lower-limb amputees. Amputees in the Developing World amputees lack this technology. Most current Developing World prosthetic solutions do not adequately address the needs of active amputees and were not designed to pass international standard tests. Developing a low-cost, repairable, adjustable, energy storage and return prosthetic foot would close this technological gap and improve the mobility and function of active amputees. The goal of this research is to determine the feasibility of fabricating a low-cost, adjustable, ESAR, repairable prosthetic foot manufactured from carbon fiber …

Effect Of Multi-Tube Injector Geometry On Flame Stability And Nox Emission In A High Pressure Gas Turbine Combustor, Sudipa Sarker

Open Access Theses & Dissertations

Future generation gas turbine combustors for power production are expected to have the capability of operating on high hydrogen content fuels. To ensure the implementation of high hydrogen content (HHC) fuel in a power generation unit without negotiating with operational or emission advantages, the study of the flame stability regime and behavior of (HHC) fuel under gas turbine condition leads to the necessity of the development of an optically accessible high-pressure combustor. This Dissertation first presents the design of an optically high-pressure combustor facility based on 500 kW power and 1.5 MPa pressure which is the representative pressure of a …

An Experimental Investigation Of The Cooling Channel Geometry Effects On The Internal Forced Convection Of Liquid Methane, Adrian Trejo

Open Access Theses & Dissertations

Rocket engine fuel alternatives have been an area of discussion for use in high performance engines and deep spaceflight missions. In particular, LCH4 has showed promise as an alternative option in regeneratively cooled rocket engines due to its non-toxic nature, similar storage temperatures to liquid oxygen, and its potential as an in situ resource. However, data pertaining to the heat transfer characteristics of LCH4 is limited. For this reason, a High Heat Transfer Test Facility (HHTTF) at the University of Texas at El Paso's (UTEP) Center for Space Exploration Technology and Research has been developed for the purpose of flowing …

A Comparative Analysis Of Spatial Visualization Ability And Drafting Models For Industrial And Technology Education Students, Petros Katsioloudis, Vukica Jovanović, Mildred Jones

Engineering Technology Faculty Publications

The article presents the comparative study on the drafting models and spatial visualization ability of industrial and technology education students in the U.S. It discusses how the study was conducted which examined the issue based on technical drawings and with regards to the impacts of model types. The results reportedly revealed three-dimensional models are effective for promoting learning, however more studies have to be conducted.

Implementing Mechatronics Design Methodology In Mechanical Engineering Technology Senior Design Projects At The Old Dominion University, Vukica M. Jovanovic, Jennifer G. Michaeli, Otilia Popescu, Moustafa R. Moustafa, Mileta Tomovic, Alok K. Verma, Cheng Y. Lin

Engineering Technology Faculty Publications

In recent years, the nature of engineering design has changed due to advances in embedded system design and computer technologies. It is rare to engineer a purely mechanical design that does not incorporate electrical and electronic components. Mechanical engineers and mechanical engineering technologists must possess a multi-disciplinary knowledge with the understanding of both mechanical and electrical systems. For this purpose, undergraduate programs in engineering technology have added mechatronics courses to their curriculum. Mechatronics is a design process that is multi-disciplinary in nature and integrates principles of many engineering disciplines including, but not limited to, mechanical engineering, electrical engineering, and controls …

Thermal Analysis, Microstructural Characterization And Nanoindentation For Electron Beam Additive Manufacturing, Bo Chang, Xibing Gong, Xiaoqing Wang, Kevin Chou

Early Career Technical Journal (ECTJ)

Section 7: Design & Manufacturing; pp. 196-203

Thermomechanical Modeling Of Cone Sample Of Zrb2-Sic Ceramic Under Arc-Jet Conditions, Lokeswarappa R. Dharani, Jun Wei

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The effects of oxidation on mechanical behavior of a cone sample of ZrB2-SiC ceramic under arc-jet test conditions is studied by a finite element (FE) model. First a steady-state heat transfer FE method was employed to conduct the thermal analysis and obtain the temperature distribution in the inner body of the cone. Then, resulting temperature distribution is applied to the thermomechanical finite element analysis to calculate the thermal stress distribution in the cone body. Due to the mismatch of material properties between the bulk ZrB2-SiC and its new products after oxidation, the outer oxide layers constrain the thermal deformation of …

Approximate Dynamic Programming, Local Or Global Optimal Solution?, Ali Heydari, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of global optimality analysis of approximate dynamic programming-based solutions is investigated in this study. Sufficient conditions for global optimality are obtained without requiring the state penalizing terms in the cost function or the functions representing the dynamics to be convex functions. Afterwards, the theoretical results are confirmed through a qualitative analysis of an example problem. © 2014 American Automatic Control Council.

Optimal Switching Of Nonlinear Systems With Free Mode Sequence, Ali Heydari, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Approximate dynamic programming is utilized in this study to develop solutions for optimal switching problems. The order of the active subsystems and the number of switches are free, and an online solution is developed that produces optimal performance. Motivated by the development in the adaptive critic's literature, the proposed method uses a critic and as many actors as the number of subsystems in order to conduct optimal scheduling in real-time based on the instantaneous states of the system. It is observed that once the neural networks are trained offline based on the proposed algorithm, they provide solutions for a range …

A Novel Microgrid Demand-Side Management System For Manufacturing Facilities, Terance J. Harper, William J. Hutzel, James C. Foreman, Aaron L. Adams, Athula Kulatunga

Purdue Polytechnic Masters Theses

Thirty-one percent of annual energy consumption in the United States occurs within the industrial sector, where manufacturing processes account for the largest amount of energy consumption and carbon emissions. For this reason, energy efficiency in manufacturing facilities is increasingly important for reducing operating costs and improving profits. Using microgrids to generate local sustainable power should reduce energy consumption from the main utility grid along with energy costs and carbon emissions. Also, microgrids have the potential to serve as reliable energy generators in international locations where the utility grid is often unstable.

For this research, a manufacturing process that had approximately …

Strain Modulations As A Mechanism To Reduce Stress Relaxation In Laryngeal Tissues, Eric J. Hunter, Thomas Siegmund, Roger W. Chan

School of Mechanical Engineering Faculty Publications

Vocal fold tissues in animal and human species undergo deformation processes at several types of loading rates: a slow strain involved in vocal fold posturing (on the order of 1 Hz or so), cyclic and faster posturing often found in speech tasks or vocal embellishment (1–10 Hz), and shear strain associated with vocal fold vibration during phonation (100 Hz and higher). Relevant to these deformation patterns are the viscous properties of laryngeal tissues, which exhibit non-linear stress relaxation and recovery. In the current study, a large strain time-dependent constitutive model of human vocal fold tissue is used to investigate effects …

Analysis Of A Dual Scissored-Pair,Variable-Speed, Control Moment Gyroscope Driven Spherical Robot, Richard Chase

Wayne State University Dissertations

The objective of this research is to compare barycenter offset based designs of spherical robots to control moment gyroscope (CMG) based designs in order to determine which approach is most effective. The first objective was to develop a list of current state of the art designs in order to gain an overall understanding of what the obstacles in this area of research were. The investigation showed that barycenter offset designs can produce a low, continuous output torque, whereas CMG based designs can usually only produce a high, momentary output torque. The second objective was to develop a CMG based design …

Pedestrian Head Protection During Car To Pedestrian Accidents: In The Event Of Primary Impact With Vehicle And Secondary Impact With Ground, Vishal Gupta

Wayne State University Dissertations

Current regulations for assessing pedestrian safety use a simplified test setup that ignores many real-world factors. In particular, the level of protection is assessed using a free-motion headform impacting the vehicle's hood at a fixed angle. As such, this test setup does not capture the effect due to the vehicle front-end profile, nor does it comprehend injury due to a possible secondary impact of the pedestrian's head with ground. This thesis aims to numerically simulate vehicle to pedestrian crashes to develop knowledge that may suggest ways to improve safety above and beyond the regulatory tests. Inputs to the simulations include …

Study Of Chaotic Ultrasound And Frequency Sweep Excitations In Sonic Ir Nde Technology, Ding Zhang

Wayne State University Dissertations

Sonic Infrared (IR) Imaging Nondestructive Evaluation (NDE) technology has shown inherent advantages, such as fast detection for all direction and all dimension flaws, for both metal and composite materials. The purpose of this dissertation is to study and investigate the physical process of two most important methods, frequency sweep excitation and chaotic excitation, to improve the defect detection ability of Sonic IR technology.

The tool used in our study is known as finite element analysis (FEA). According to test process of Sonic IR technology, some special technologies were developed in FEA simulation, such as creating cracks with flat contact surfaces …

Effect Of Cetane Number And Volatility On Autoignition And Combustion Of Alternative Fuels And Their Surrogates, Ziliang Zheng

Wayne State University Dissertations

Diesel engine has become a popular choice for trucks, trains, boats, and most other heavy-duty applications. The inherent benefits of diesel engine are high thermal efficiency and specific power output, but there is a concern about high levels of engine-out NOx and particulate matter emissions, which is a major contributor in environment pollution. Moreover, concern about the crisis of crude oil reserves, increasing gas price, trade deficit, and homeland security enhances the interests in alternative fuels.

Unlike conventional diesel fuel, alternative fuels have wide range of properties, such as volatility, cetane number, density, viscosity and lower heating value, which influence …

Communication Protocol Design Considerations For Highway Vehicle Platoons And Enhanced Networked Robustness By Stochastic Dithers, Lijian Xu

Wayne State University Dissertations

Highway platooning of vehicles has been identified as a promising framework in

developing intelligent transportation systems. By autonomous or semi-autonomous

vehicle control and inter-vehicle coordination, an appropriately managed platoon can

potentially offer enhanced safety, improved highway utility, increased fuel economy,

and reduced emission. This thesis is focused on quantitative characterization of impact

of communication information structures and contents on platoon safety. By

comparing different information structures which combine front sensors, rear sensors,

and wireless communication channels, and different information contents such

as distances, speeds, and drivers' actions, we reveal a number of intrinsic relationships

between vehicle coordination and communications in …

High-Performance Accelerometer Based On Asymmetric Gapped Cantilevers For Physiological Acoustic Sensing, Yating Hu

Wayne State University Dissertations

Continuous or mobile monitoring of physiological sounds is expected to play important role in the emerging mobile healthcare field. Because of the miniature size, low cost, and easy installation, accelerometer is an excellent choice for continuous physiological acoustic signal monitoring. However, in order to capture the detailed information in the physiological signals for clinical diagnostic purpose, there are more demanding requirements on the sensitivity/noise performance of accelerometers. In this thesis, a unique piezoelectric accelerometer based on the asymmetric gapped cantilever which exhibits significantly improved sensitivity is extensively studied. A meso-scale prototype is developed for capturing the high quality cardio and …

Non-Linear Robust Observers For Systems With Non-Collocated Sensors And Actuators, Constantine Mastory

Wayne State University Dissertations

Challenges in controlling highly nonlinear systems are not limited to the development of sophisticated control algorithms that are tolerant to significant modeling imprecision and external disturbances. Additional challenges stem from the implementation of the control algorithm such as the availability of the state variables needed for the computation of the control signals, and the adverse effects induced by non-collocated sensors and actuators.

The present work investigates the adverse effects of non-collocated sensors and actuators on the phase characteristics of flexible structures and the ensuing implications on the performance of structural controllers. Two closed-loop systems are considered and their phase angle …

Jp-8 Surrogates For Diesel Engine Application: Development, Validation, And Cfd Simulation, Amit Shrestha

Wayne State University Dissertations

Recently, diesel engine cycle simulation has been acknowledged as an effective way for the development and performance optimization of compression ignition engines operating on a variety of fuels. The goal of this research was, therefore, to develop a JP-8 surrogate with a limited number of fuel components so that its chemical mechanism could be developed for its use with computational fluid dynamics (CFD) codes for enabling time-efficient diesel engine cycle simulation. In order to achieve this goal, a new approach was developed for the formulation of surrogate for compression ignition engine application. The development approach required the surrogate to match …

Evaluation Of Nozzle Geometry On High Pressure Gasoline Direct Injection Spray Atomization, Mark Shost

Wayne State University Dissertations

This research presents a critical study of injector nozzle geometry on high-pressure Gasoline Direct Injection, GDi, injector spray morphology. The study was conducted with the aid of multi-fluid Volume-of-Fluid, Large-Eddy-Simulation, VOF-LES, method. Alternative nozzle geometries, that are the subject of current interest including varying nozzle hole length to diameter ratio, counter-bore presence and nozzle-hole skew-angle geometry, are studied in detail in order to provide insight into their specific influence on spray plume targeting and jet primary breakup characteristics. A comparison of the simulation results with near-field shadowgraph and Mie scatter imaging as well as phase-contrast x-ray imaging is provided. When …

Finite Element Analysis Of Shear Resistant Mechanisms For Biolaminate Interfaces, Matthew Nelms

Electronic Theses and Dissertations

The Alligator gar possesses a flexible dermal armor consisting of overlapping ganoid scales. Each scale is a bilayer hydroxyapatite and collagen-based bio-laminate for protection against predation. The exoskeleton fish scale is comprised of a stiff outer ganoine layer, a characteristic "sawtooth" pattern at the interface and a compliant bone inner layer with all materials exhibiting a decreasing elastic modulus, yield strength and density through the thickness. Experiments on ganoid scales revealed properties such as damage mitigation and energy dissipation that are unique to biological dermal armor. The objective of this investigation is to develop a fundamental understanding of the stress …

Combustion Visualization And Particulate Matter Emission Of A Gdi Engine By Using Gasoline And E85, Po-I Lee

Wayne State University Dissertations

In order to increase engine efficiency as well as to reduce emission, optimizing combustion is always the challenge in research and product development. Gasoline direct injection (GDI) engines have been popularized due to its higher power density, fuel efficiency, and the possibility for advanced engine technologies over conventional port-fuel-injection (PFI) gasoline engines. However, many issues are heavily investigated, such as air-fuel mixing preparation, fuel wall-wetting, higher HC and PM emissions, catalytic convertor efficiency, knocking, and pre-ignition. Besides, advanced technologies represent higher production cost.

Because of the limited resource of petroleum-based fuels, ethanol is deemed as the alternative fuel for gasoline …

Visualizing Interior And Exterior Jet Aircraft Noise, Manmohan Singh Moondra

Wayne State University Dissertations

In today's competitive aerospace industry, the quest for quiet has drawn significant attention to both the interior and exterior design of an airplane. Understanding the noise generation mechanisms of a jet aircraft is a crucial first step toward developing the most cost-effective noise and vibrations abatement methods. In this investigation, the Helmholtz Equation Least Squares (HELS) based nearfield acoustic holography will be used to understand noise transmission caused by jet engine and turbulence into the fuselage of a jet aircraft cruising at 30,000 ft.

Modern propulsive jet engines produce exterior noise sources with a high amplitude noise field and complicated …