Mechanical Engineering Commons^™

Integrated Sustainability Decision-Making Framework, Michael Paul Cole

Open Access Theses & Dissertations

The Integrated Sustainability Decision-Making Framework (ISDMF) is an 'ideal case' framework developed at the University of Texas El Paso (UTEP) from 2012 to present to provide the most comprehensive and concise sustainability strategy and decision-making template available.

Sustainable decision-making improves community Quality of Life, but is often beyond the reach of the majority. A framework that is most approachable, actionable, and adoptable can accelerate convergence on and continued operation of a sustainable solution. Research confirms that published frameworks continuously emerge, and are infinite in number. Iterations benefit from prior work, and contribution occurs when an 'ideal case' is envisioned, best …

An Experimental Investigation On Liquid Methane Heat Transfer Enhancement Through The Use Of Longitudinal Fins In Cooling Channels, Manuel De Jesus Galvan

Open Access Theses & Dissertations

In the past years, hydrocarbon fuels have been the focus of attention as the interest in developing reusable, high-performing liquid rocket engines has grown. Liquid methane (LCH4) has been of particular interest because of the cost, handling, and storage advantages that it presents when compared to currently used propellants. Deep space exploration requires thrusters that can operate reliably during long-duration missions. One of the challenges in the development of a reliable engine has been providing adequate combustion chamber cooling to prevent engine failure. Regenerative (regen) cooling has presented itself as an appealing option because it provides improved cooling and engine …

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 …

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 …

Hydrogen Generation From Ammonia Borane And Water Through The Combustion Reactions With Mechanically Alloyed Al/Mg Powder, Daniel Rodriguez

Open Access Theses & Dissertations

Finding and developing a safe and effective method for hydrogen storage is integral to its use as an alternative source of energy. The goal of the studies described in this Thesis was to investigate the feasibility of developing combustible hydrogen-generating compositions based on ammonia borane and novel energetic materials such as nanocomposite and mechanically alloyed reactive materials, recently obtained by Prof. Edward Dreizin's team at the New Jersey Institute of Technology (NJIT). Such compositions could be stored for long time and release hydrogen on demand, upon ignition. The first phase of the research included thermodynamic calculations for combustion of ammonia …

Design Optimization Of The Heat Transfer Model For A High Heat Flux Test Facility, Linda Hyemin Yoon

Open Access Theses & Dissertations

There are a variety of fuels that are utilized for space applications and in recent years, environmentally friendly fuels have been of interest. In the case of bipropellant rocket systems, hydrocarbon fuels have come to the attention of scientists and engineers. In particular, liquid methane was of interest in this study because of its physical and chemical advantages over other fuels, such as liquid hydrogen. Rocket engines rise to very high temperatures and to avoid catastrophic mechanical failure, a cooling system must be implemented within the engine to cool the walls. To get a better understanding of the fluid flow …

A Circuit-Based Algorithm For Two-Phase Flow At The Pore Scale In Porous Media, Todd Dorethy

Open Access Theses & Dissertations

Models of two-phase flow in porous media are of practical interest in many fields of science and engineering such as in oil recovery and hydrology. For this class of problem, an immiscible fluid is injected into a single-phase, porous medium to evict its valuable, native fluid. Because the aim is to amass as much of the indigenous fluid as possible, models attempt to output reliable flow regime patterns depicting how well the invading fluid displaces the native fluid.

Flow regime patterns generally depend upon the geometry of the domain, stimulation at the boundaries, and properties of the invading and native …

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 …

Numerical Prediction Of Collection Efficiency Of A Personal Sampler Based On Cyclone Principle, Antara Badhan

Open Access Theses & Dissertations

A personal bioaerosol sampler is a self-contained, operation flexible, high-efficient device for indoor air quality (IAQ) and health risk exposure monitoring and measurement. Bio-aerosols such germ-laden viruses, microbial species, airborne microorganisms and volatile organic compounds (VOC) are sucked into the sampler and are deposited on the inner wall surface based on cyclone principal. The major concern with bio-aerosol samplers is the collection efficiency. In this study, we used computational fluid dynamics (CFD) tools to evaluate key design parameters, specifically the inlet tube angle and collection tube inner wall roughness. 3D incompressible turbulent flow was simulated using commercial software ANSYS FLUENT. …

Gas-Solid Bed Hydrodynamics Of Non-Spherical Particles, A S M Raufur Rahim Chowdhury

Open Access Theses & Dissertations

Gas-solid beds are ubiquitous in industrial and energy production applications. Examples include fluidized beds, which are used in many systems such as in Integrated Gasification Combined Cycle (IGCC) power plants or in chemical looping systems. These examples and others involve complicated interactions between each phase of reactants in the system. The motivation of this work stems from the need for a better understanding of bed hydrodynamics in existing energy systems; results from this work can be used directly in software such as Fluent to more accurately predict flow behaviors of gas and solid phases. The experimental data are collected from …

A Study On The Role Of Physical Models In The Mitigation Of Design Fixation, Vimal Viswanathan, Olufunmilola Atilola, Nicole Esposito, Julie Linsey

Faculty Publications, Mechanical Engineering

Designers implement a variety of models and representations during the design process, yet little is known about the cognitive impacts of various representations. This study focuses on how physical models can assist novices in mitigating design fixation on undesirable features. During idea generation, designers tend to fixate on examples they encounter or on their own initial ideas. The first hypothesis states that designers tend to duplicate features of provided examples. The second hypothesis states that this fixation can be mitigated with appropriate warnings. The last hypothesis is that building and testing physical models can help designers in mitigating fixation. To …

Crack Self-Healing In Sic/Spinel Nanocomposite, Fariborz Tavangarian

LSU Doctoral Dissertations

Spinel is one of the best known and widely used ceramic materials. It has good thermal shock resistance, high chemical inertness in both acidic and basic environments, excellent optical and dielectric properties, high strength at both elevated and normal temperatures, and has no phase transition up to the melting temperature (2135°C). Spinel is used in the metallurgical, electrochemical, and chemical industrial fields. It has also found some applications in dentistry, catalyst supports, humidity sensors, reinforcing fibers, photoluminescent materials, etc. One of the limitations of spinel ceramic is its brittleness. Furthermore, at high temperature applications, a rapid heating or cooling can …

Meso-Scale Analysis Of Deformation Induced Heating In Granular Metalized Explosives By Piston Supported Waves, Sunada Srinath Nagamani Chakravarthy

LSU Doctoral Dissertations

Shock sensitivity of heterogeneous explosive composites is dependent on the formation of hot-spots which are small regions of elevated temperatures within the material. Changes in the initial meso-structure (i.e. packing density, composition, particle size and shapes) of the explosives can significantly alter the hot-spot fields in the material and thereby affect its shock sensitivity. In this study, an explicit, 2D, Lagrangian finite and discrete element technique is used to numerically simulate the deformation induced heating of granular mixtures of explosive (HMX), and metal (Al) particles due to piston supported uniaxial deformation waves (400 ≤ Up ≤ 800 m/s). A number …

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 …

Molecular Dynamics Simulations Of Pure Polytetrafluoroethylene Near Glassy Transition Temperature For Different Molecular Weights, Rawan Al-Nsour

Theses and Dissertations

Fluoropolymers are employed in countless end-user applications across several industries. One such fluoropolymer is polytetrafluoroethylene. This research is concerned with studying and understanding the thermal behavior of polytetrafluoroethylene. Such understanding is critical to predict its behavior in diverse service environments as the polymer ages and for allowing bottom up design of improved polymers for specific applications.

While a plethora of experiments have investigated the thermal properties of polytetrafluoroethylene, examining these properties using molecular dynamics simulations remains in its infancy. In particular, the current body of molecular dynamics research on polytetrafluoroethylene has primarily focused on studying polytetrafluoroethylene phases, its physical nature, …

Standoff Methods For The Detection Of Threat Agents: A Review Of Several Promising Laser-Based Techniques, J. Bruce Johnson, Susan D. Allen, Jonathan Merten, Lewis Johnson, Daniel Pinkham, Scott W. Reeve

Publications

Detection of explosives, explosive precursors, or other threat agents presents a number of technological challenges for optical sensing methods. Certainly detecting trace levels of threat agents against a complex background is chief among these challenges; however, the related issues of multiple target distances (from standoff to proximity) and sampling time scales (from passive mines to rapid rate of march convoy protection) for different applications make it unlikely that a single technique will be ideal for all sensing situations. A number of methods for spanning the range of optical sensor technologies exist which, when integrated, could produce a fused sensor system …

Modeling Of Chemical-Mechanical Couplings In Solid Oxide Cells And Reliability Analysis, Xinfang Jin

Theses and Dissertations

Solid oxide fuel cell (SOFC) has been well demonstrated as a promising clean energy conversion technology. For practical applications, the SOFC systems should have both good electrochemical performance and high reliability. The SOFCs are usually operated under very aggressive conditions, e.g., high temperatures (600-1000oC) and extremely low oxygen partial pressures (anode electrode). These aggressive operating conditions could lead to a variety of material system degradations, imposing great challenges on meeting lifetime requirement of SOFC commercial applications. It is therefore essential to increase the understanding of fundamental SOFC degradation mechanisms.

The basic structure of SOFCs is a positive electrode-electrolyte-negative electrode (PEN) …

Electrospinning Applications Air Filtration And Superhydrophobic Materials, Negar Ghochaghi, Adetoun Taiwo

Graduate Research Posters

Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers. …

System-Level Simulation Of A Solar Power Tower Plant With Thermocline Thermal Energy Storage, Scott M. Flueckiger, Brian D. Iverson, Suresh V. Garimella, James E. Pacheco

Faculty Publications

A thermocline tank is a low-cost thermal energy storage subsystem for concentrating solar power plants that typically utilizes molten salt and quartzite rock as storage media. Longterm thermal stability of the storage concept remains a design concern. A new model is developed to provide comprehensive simulation of thermocline tank operation at low computational cost, addressing deficiencies with previous models in the literature. The proposed model is then incorporated into a system-level model of a 100 MWe power tower plant to investigate storage performance during long-term operation. Solar irradiance data, taken from measurements for the year 1977 near Barstow, CA, are …

Low Frequency Energy Scavenging Using Sub-Wave Length Scale Acousto-Elastic Metamaterial, Raiz U. Ahmed, Sourav Banerjee

Faculty Publications

This letter presents the possibility of energy scavenging (ES) utilizing the physics of acousto-elastic metamaterial (AEMM) at low frequencies (<∼3KHz). It is proposed to use the AEMM in a dual mode (Acoustic Filter and Energy Harvester), simultaneously. AEMM’s are typically reported for filtering acoustic waves by trapping or guiding the acoustic energy, whereas this letter shows that the dynamic energy trapped inside the soft constituent (matrix) ofmetamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. With unit cell AEMM model, we experimentally asserted that at lower acoustic frequencies (< ∼3 KHz), maximum power in the micro Watts (∼35µW) range can be generated, whereas, recently reported phononic crystal based metamaterials harvested only nano Watt (∼30nW) power against 10KΩ resistive load. Efficient energy scavengers at low acoustic frequencies are almost absent due to large required size relevant to the acoustic wavelength. Here we report sub wave length scale energy scavengers utilizing the coupled physics of local, structural and matrix resonances. Upon validation of the argument through analytical, numerical and experimental studies, a multi-frequency energy scavenger (ES) with multi-cellmodel is designed with varying geometrical properties capable of scavenging energy (power output from ∼10µW – ∼90µW) between 0.2 KHz and 1.5 KHz acoustic frequencies.

Ni-Doped Sr2Fe1.5Mo0.5O6-Δ As Anode Materials For Solid Oxide Fuel Cells, Guoliang Xiao, Siwei Wang, Ye Lin, Zhibin Yang, Minfang Han, Fanglin Chen

Faculty Publications

10% Ni-doped Sr₂Fe_1.5Mo_0.5O_6-δ with A-site deficiency is prepared to induce in situ precipitation of B-site metals under anode conditions in solid oxide fuel cells. XRD, SEM and TEM results show that a significant amount of nano-sized Ni-Fe alloy metal phase has precipitated out from Sr_1.9Fe_1.4Ni_0.1Mo_0.5O_6-δ upon reduction at 800^◦C in H₂. The conductivity of the reduced composite reaches 29 S cm⁻¹ at 800^◦C in H₂. Furthermore, fuel cell performance of the composite anode Sr_{1.9 …}

Modelling Of Biomass Gasification Integrated With A Solid Oxide Fuel Cell System, Wayne Doherty

Doctoral

Biomass is of major interest as a renewable energy source in the context of climate change and energy security. Traditional biomass conversion technologies achieve low electrical efficiencies. Biomass gasification (BG) coupled with fuel cells offer higher efficiencies. Gasification is a process in which a carbonaceous fuel is converted to a combustible gas. It occurs when a controlled amount of oxidant is reacted at high temperatures with available carbon in a fuel within a gasifier. Two technologies (circulating fluidised bed air gasification and dual fluidised bed steam gasification) were modelled. Solid oxide fuel cells (SOFCs) are well suited to integration with …

Magnetic Nanoparticles For Thermally Anoparticles Enhanced Heavy Oil Recovery, Hazem Elshorbagy Elshorbagy

Theses

A novel method of delivering thermal energy efficiently to reservoirs for heavy oil production is described in this study. The method uses magnetic nanoparticles that generate heat locally when exposed to a high frequency magnetic field oscillation via hysteresis losses. This concept is currently used in medical research to thermally kill cancerous cells. Electromagnetic heating is a n alternative method to heat heavy oil reservoirs without using water or steam. Using magnetic nanoparticles with electromagnetic heating would greatly reduce the energy requirement and would allow efficient propagation of heat into deeper regions beyond wellbore locality that are otherwise difficult to …

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 …

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 …

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 …

Applying Spiking Neural Network Simulation To Neuromodulatory Autonomous Robot Control, Cameron Muhammad

Phi Kappa Phi Research Symposium (Archived)

In this paper, simulation of the brain based on an artificial spiking neuron model is used to create a self-learning algorithm. The spiking neuron simulation is used to demonstrate a neuromodulation program in which the reward seeking properties of dopamine, the risk-adverse effects of serotonin, and the attention-focusing effects of the cholinergic and noradrenergic systems are applied to a mobile robotic platform as it moves autonomously throughout an environment. External stimuli is recorded by the program as spiking “events” that result in corresponding amounts of dopamine and serotonin influenced spiking patterns. These spiking patterns affect how the robot adapts to …

There Can Be Turbulence In Microfluidics At Low Reynolds Number, Guiren Wang, F. Yang, Wei Zhao

Faculty Publications

Turbulence is commonly viewed as a type of macroflow, where the Reynolds number (Re) has to be sufficiently high. In microfluidics, when Re is below or on the order of 1 and fast mixing is required, so far only chaotic flow has been reported to enhance mixing based on previous publications since turbulence is believed not to be possible to generate in such a low Re microflow. There is even a lack of velocimeter that can measure turbulence in microchannels. In this work, we report a direct observation of the existence of turbulence in microfluidics with Re on the order …

Neuromodulation Based Control Of Autonomous Robots On A Cloud Computing Platform, Cameron Muhammad

College of Graduate Studies: Theses & Dissertations

In recent years, the advancement of neurobiologically plausible models and computer networking has resulted in new ways of implementing control systems on robotic platforms. The work presents a control approach based on vertebrate neuromodulation and its implementation on autonomous robots in the open-source, open-access environment of robot operating system (ROS). A spiking neural network (SNN) is used to model the neuromodulatory function for generating context based behavioral responses of the robots to sensory input signals. The neural network incorporates three types of neurons- cholinergic and noradrenergic (ACh/NE) neurons for attention focusing and action selection, dopaminergic (DA) neurons for rewards- and …

Impact Of Fracture Spacing And Mechanical Parameter Anisotropy On Fracture Width In Horizontal Wells In Shales, Deepak Gokaraju

Masters Theses

"The success of economically viable production of oil and gas from ultra-low permeability shale reservoirs depends on the creation of an extensive fracture network through hydraulic fracture stimulation. Multiple hydraulic fractures are created simultaneously in each stage to increase the surface area of contact between the wellbore and reservoir. The spacing between fractures is an important component to consider when developing an optimum stimulation design. An important aspect of shale rock properties is that shales are inherently anisotropic with a horizontal plane of isotropy (transversely isotropic) due to their finely layered structure. This study aims to provide an insight into …