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Theses and Dissertations

2018

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Full-Text Articles in Mechanical Engineering

Equivalent Circuit Model Generation For Batteries Using Non-Ideal Test Data, Logan Crain Dec 2018

Equivalent Circuit Model Generation For Batteries Using Non-Ideal Test Data, Logan Crain

Theses and Dissertations

Modeling is a key component in the development of battery products. While there are multiple levels of complexity which may be achieved in model development, equivalent circuit modeling is able to quickly produce reliable and accurate predictions for battery behavior. While the use of equivalent circuit models has been described in great detail for lithium ion batteries, it is also desirable to use this methodology regardless of chemistry, specifically with respect to lead-acid technology. When developing battery models for predicting battery behavior in a vehicle, the testing methods meant to mimic vehicle applications often cause non-ideal data for model generation. …

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Applications Of Dynamic Mode Decomposition And Sparse Reconstruction In The Data-Driven Dynamic Analysis Of Physical Systems, Mojtaba F. Fathi Dec 2018

Applications Of Dynamic Mode Decomposition And Sparse Reconstruction In The Data-Driven Dynamic Analysis Of Physical Systems, Mojtaba F. Fathi

Theses and Dissertations

Recent advancements in data collection methods and equipment have resulted in a huge increase in the amount of data collected by observing various types of physical phenomena. Regardless of the amount of data collected, it is well known for many physical systems, the so-called information rank of the collected data is much lower than the rank of the data itself. This usually means the data may be represented sparsely in terms of a properly-chosen basis. This realization has led to methods for storing large amounts of data through compression by sacrificing negligible data quality. More importantly, with the advent of …

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Transient Analysis Of A Coolant-To-Refrigerant Heat Exchanger To Provide Temporary High Performance In An Automotive Vehicle, Abhinav Ravi Dec 2018

Transient Analysis Of A Coolant-To-Refrigerant Heat Exchanger To Provide Temporary High Performance In An Automotive Vehicle, Abhinav Ravi

Theses and Dissertations

The objective of this thesis is to provide a numerical and experimental design tool to understand the heat transfer analysis of a coolant reservoir being chilled at a sub-ambient temperature with a goal of eventually providing a transient burst in performance. A high performance vehicle usually has a liquid charge air cooler that cools air before entering the engine. This liquid charge air cooler cools the air by using a specific coolant coming from the low temperature radiator. This study involves a coolant reservoir independent of the low-temperature radiator to provide coolant at a sub-ambient temperature to the liquid charge …

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Radiative Heat Transfer Analysis Of Railroad Bearings For Wayside Thermal Detector Optimization, James Alexandro Aranda Dec 2018

Radiative Heat Transfer Analysis Of Railroad Bearings For Wayside Thermal Detector Optimization, James Alexandro Aranda

Theses and Dissertations

Wayside hot-box detectors (HBDs) are devices that are currently used to evaluate the health of railcar components including bearings, axles, and brakes by monitoring their temperatures. While HBDs have been instrumental in reducing some train derailments in the past few decades, the number of non-verified bearing removals has increased significantly. In general, HBDs tend to underestimate bearing temperatures in both field service and in laboratory testing, which is not surprising considering the simple two-point calibration method that is used to calibrate these devices. Because of this, different calibrations were compared and analyzed including two-point, three-point, and multi-point calibrations. Analysis of …

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Synthesis And Design Of Metals Sulfide/Carbon Composite-Fibers Anodes For Lithium Ion Batteries, Jorge Lopez Dec 2018

Synthesis And Design Of Metals Sulfide/Carbon Composite-Fibers Anodes For Lithium Ion Batteries, Jorge Lopez

Theses and Dissertations

In this study, Forcespinning is used to produce Titanium sulfide (TiS2)/carbon composite fibers for use as lithium-ion battery anodes. The high surface area to volume ratio of the composite fibers can have a high impact on the ionic and electronic conductivity of the active materials leading to improved electrochemical performance of the battery. TiS2 nanoparticles were chosen as the active materials to produce Metal-Li-alloys/C composite fibers due to their high theoretical capacity and low volume change during charge/discharge cycles. The use of a 2-D layered structure of TiS2 nanoparticles in the carbon fiber matrix can greatly accommodate more Li-ions between …

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Improving Thermal-Hydraulic Performance Of Flat-Tube Louver-Fin Heat Exchangers By Eliminating Louver Gap Condensate Bridges, Alan L. Jones Dec 2018

Improving Thermal-Hydraulic Performance Of Flat-Tube Louver-Fin Heat Exchangers By Eliminating Louver Gap Condensate Bridges, Alan L. Jones

Theses and Dissertations

The air side performance of heat exchangers is a well studied subject. Flat-tube louver-fin heat exchangers experience a decrease in performance when operating in dehumidifying conditions. As water vapor is pulled from the air, water condensate may create blockages between louvers. Flat-tube louver-fin heat exchanger may experience a drop in thermal-hydraulic performance by up to 50% due to blockages. The aim of this study is to make macro scale geometric changes to louver dimensions and eliminate louver condensate bridges. By eliminating louver condensate blockages, the heat exchanger should see an overall gain in thermal performance when compared to current fin …

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Aligning Anatomical Knee Model With Kinematic Experimental Data To Investigate Squat Exercise, Jose Mario Salinas Dec 2018

Aligning Anatomical Knee Model With Kinematic Experimental Data To Investigate Squat Exercise, Jose Mario Salinas

Theses and Dissertations

A two-dimensional inverse dynamics anatomical model of the human knee was developed by aligning anatomical structures of the knee (taken from x-rays) with kinematic experimental data (collected from motion capture cameras). The mathematical model was used to study the forces related to the tibiofemoral and patellofemoral joints during the squat and knee extension exercises. Forces calculated by the model included: tibiofemoral contact force, patellofemoral contact force, forces generated by cruciate ligaments, quadriceps force, and patellar tendon force. Bone alignment consisted of superimposing the geometric center of the lateral femoral condyle (from x-rays) with the relative instantaneous center of rotation of …

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Vision-Based Navigation For Electromagnetic Formation Flight, Nasir Ghazi Hariri Dec 2018

Vision-Based Navigation For Electromagnetic Formation Flight, Nasir Ghazi Hariri

Theses and Dissertations

The concept of using Satellite Formation Flight (SFF) reveals various benefits for a space mission. However, relying on a consumable actuation system to maintain a desired relative position and orientation between flying satellites has hindered its practicality and feasibility for long duration missions. By adapting the SFF concept such that electromagnetic actuation mechanism is employed, the concept of Electromagnetic Formation Flight (EMFF) offers a great potential to validate such a technology. EMFF provides interacting forces and torques between flying satellites to maintain their relative position within a formation using its electromagnetic actuation capabilities. This dissertation demonstrates the possibilities of utilizing …

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A Systematic Approach To High Blood Pressure Risk Analysis And Healthcare Cost Reduction In Young Adults [Metodología Sistemática Para El Análisis De Riesgo Y Reducción De Costos De Servicios Médicos De Hipertensión En Adultos Jóvenes], Francisco Rafael Torres Diaz Dec 2018

A Systematic Approach To High Blood Pressure Risk Analysis And Healthcare Cost Reduction In Young Adults [Metodología Sistemática Para El Análisis De Riesgo Y Reducción De Costos De Servicios Médicos De Hipertensión En Adultos Jóvenes], Francisco Rafael Torres Diaz

Theses and Dissertations

The purpose of this research is to utilize publicly available data to estimate the current rate of occurrence of undiagnosed High Blood Pressure (HBP) in young adults (18 to 24 years old) and the out-of-pocket healthcare expenses associated with complications of HBP, to provide feasible alternatives to mitigate the effects on a region's economy. This has been done by building a Risk Factor Simulation Model that utilizes known HBP risk factors’ correlation to HBP, insurance coverage data, and rate of diagnosis to formulate the average Risk Factor Value for a region, which through an Annual Expected Cost Function estimates the …

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Three Dimensional Nonlinear Simulation Of Quench Phenomenon In Superconducting Tapes Using Mesh-Free Monte-Carlo Method, Reza Bahadori Dec 2018

Three Dimensional Nonlinear Simulation Of Quench Phenomenon In Superconducting Tapes Using Mesh-Free Monte-Carlo Method, Reza Bahadori

Theses and Dissertations

Performing quench propagation simulations of full size superconducting coils is a challenging problem due to complex coil structures and internal arrangements of superconducting wires. In addition, superconducting wires and cables themselves constitute complex 3D arrangements comprised of superconductor, matrix, stabilizer, insulation and other materials. Modelling quenches in complete coils is therefore a complex multi-scale and multi-physics problem that is difficult to solve with conventional techniques like finite element or finite difference methods. Monte-Carlo methods have been successfully used to simulate various multi-scale and multi-physics problems, but to our knowledge have not been applied to quench propagation simulations. In the first …

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Development, Testing, Analysis, And Efficiency Of A Variable Area Dredge In Combination With A Mobile Ferrate-Based Treatment Facility, Leigh Ann Provost Dec 2018

Development, Testing, Analysis, And Efficiency Of A Variable Area Dredge In Combination With A Mobile Ferrate-Based Treatment Facility, Leigh Ann Provost

Theses and Dissertations

This thesis proposal outlines the development and testing of a mobile slurry treatment trailer coupled with a variable area suction head and further expands on results and procedures shown in Feasibility of Muck Removal in the IRL Watershed and Subsequent Ferrate Treatment to Remove Excess Nutrients. The purpose of this thesis is to evaluate the efficiency and effectiveness of the suction head based on the percent solids maintained during dredging. This thesis also evaluates a scaled design and associated costs for a fully scaled dredging project utilizing the suction head. Additional statistics involving further fitting sediment data to a Weibull …

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Coordination And Control For A Team Of Mobile Robots In An Unknown Dynamic Environment, Sucheta Roy Dec 2018

Coordination And Control For A Team Of Mobile Robots In An Unknown Dynamic Environment, Sucheta Roy

Theses and Dissertations

This research presents a dual-level control structure for controlling a mobile robot or a group of robots to navigate through a dynamic environment (such as an object is moving in the workspace of a robot). The higher-level controller operates in cooperation with robot’s state estimation and mapping algorithm, Extended Kalman Filter – Simultaneous Localization and Mapping (EKFSLAM), and the lower-level controller (PID) controls the motion of the robot when it, encounters an obstacle, i.e., it reorients the robot to a predefined rebound angle and move it straight to maneuver around the obstacle until the robot is out of the obstacle …

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The Corrosion And Biofouling Characteristics Of Sealed Vs. Perforated Offshore Monopile Interiors: Experiment Design Comparing Corrosion And Environment Inside Steel Pipe, Monica M. Maher Dec 2018

The Corrosion And Biofouling Characteristics Of Sealed Vs. Perforated Offshore Monopile Interiors: Experiment Design Comparing Corrosion And Environment Inside Steel Pipe, Monica M. Maher

Theses and Dissertations

This research addresses the need to improve on the existing methods for the corrosion control of the monopile interiors used to support wind powered turbines by incorporating a design that also enhances marine habitats and fisheries. Retrofitting monopile interiors with cathodic protection has been attempted on existing windfarms to mitigate corrosion, however, this can cause new problems including water acidification and hydrogen sulfide formation. Such chemistry changes can lead to unique localized corrosion concerns. This study investigated internal corrosion, chemistry and biofouling inside partially submerged hollow steel pipes. Watertight pipes with stagnant water inside were compared to pipes with holes …

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Computational Support For Predicting Requirement Change Volatility In Complex System Design, Phyo Htet Hein Dec 2018

Computational Support For Predicting Requirement Change Volatility In Complex System Design, Phyo Htet Hein

Theses and Dissertations

Requirements play critical role in the design process as objective statements of stakeholders’ expectations. Design process is iterative, and requirements are also constantly changed and updated to reflect stakeholders’ expectations, design changes, regulations, resource limitations, etc. Managing requirement change is one of the most important requirement management tasks. Since requirements are driving factors in product development from initial concept development stage to final production, mismanaged requirement changes can adversely affect project health leading to monetary and time losses. The ability to assess a requirement change and predict its propagation early in the design process will enable engineers to make informed …

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The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden Dec 2018

The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden

Theses and Dissertations

Over the life of nuclear fuel, inhomogeneous structures develop, negatively impacting thermal properties. New fuels are under development, but require more accurate knowledge of how the properties change to model performance and determine safe operational conditions. Measurement systems capable of small–scale, pointwise thermal property measurements and low cost are necessary to measure these properties and integrate into hot cells where electronics are likely to fail during fuel investigation. This project develops a cheaper, smaller, and easily replaceable Fluorescent Scanning Thermal Microscope (FSTM) using the blue laser and focusing circuitry from an Xbox HD-DVD player. The FSTM also incorporates novel fluorescent …

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In Silico Analysis Of Advanced Processing Methods For Light-Weight Alloys Powders, Marjan Nezafati Dec 2018

In Silico Analysis Of Advanced Processing Methods For Light-Weight Alloys Powders, Marjan Nezafati

Theses and Dissertations

Light-weight Al and Mg-based metal-matrix nanocomposites (MMNCs) are lauded as one of the most promising structural materials for vehicle, military, and construction applications. These MMNCs are often synthesized using the powder metallurgy (PM) process under liquid nitrogen cryogenic environments to control the grain sizes. It is believed that proper incorporation of the nitrogen species into the bulk lattice during processing could strongly enhance the mechanical properties of MMNCs by forming N-rich dispersoids. In this work, using the density-functional theory (DFT), the adsorption, absorption and diffusion behavior of nitrogen molecule/atoms have been studied and related to t Al and Mg MMNC …

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A Novel Numerical Method To Analyze Laminar Flow In Serrated Plate-Fin Heat Exchanger Designs, Nabila Rubaiya Dec 2018

A Novel Numerical Method To Analyze Laminar Flow In Serrated Plate-Fin Heat Exchanger Designs, Nabila Rubaiya

Theses and Dissertations

In the present research work, a simple numerical method has been explored to calculate the performance of serrated plate-fins. The numerical data of heat transfer and pressure drop performances have been compared with the available literature [6, 21], by means of calculating Chilton-Colburn j Factor and Fanning Friction Factor f, respectively. The numerical findings show good agreement with the experimental results from literature. Hence, the numerical analysis procedure proposed in this paper can be used to predict the performance of new designs of plate fins including different types of notched serrated fins. A detailed calculation and analysis of results have …

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Manufacturing Energy Consumption And Assessment For Us Small And Medium Sized Manufacturers, Yadan Zeng Dec 2018

Manufacturing Energy Consumption And Assessment For Us Small And Medium Sized Manufacturers, Yadan Zeng

Theses and Dissertations

U.S. Manufacturing sector consumes remarkable amount of energy while the energy efficiency is quite low. Energy consumption of CNC machines is significant and various empirical models have been developed to model the Specific Energy Consumption (SEC) of CNC machines. However, most of the models are developed for specific machines, hence have limited applications in manufacturing industry. In this research, a general empirical SEC model for milling machine at certain power level is developed based on actual cutting experimental data. In this model, stand-by power and spindle power are used in the SEC model for the first time. The Material Removal …

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Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson Dec 2018

Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson

Theses and Dissertations

An investigation of IsoTruss structures in bending and torsion was conducted. A model was developed in ANSYS APDL where bay length and longitudinal member to helical member cross-sectional area ratio could be varied while holding the diameter constant. The model was validated using previously reported values from analytical models and empirical data. The model was used to make predictions of a specific geometry that was manufactured, tested and compared against the model. 12 specimens were built and tested. In flexure, empirical data had a percent error with respect to the model ranging from 10.9 to 65.4% with one outlier at …

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Origami-Based Design Of Fold States And Stability, Alex Avila Dec 2018

Origami-Based Design Of Fold States And Stability, Alex Avila

Theses and Dissertations

Origami is a potentially elegant and powerful source of inspiration for many engineering designs. The viable shapes (fold states) of a single device allow it to perform multiple, seemingly contradictory, functions. The fold state is a large factor in the device's performance, but there are challenges in selecting and maintaining those fold states. In this thesis we analyze existing concepts for overcoming these challenges. Those concepts are compared with those that occur in origami-based devices. From this analysis fundamental gaps were identified, specifically, shortcoming in the terminology used to refer to (1) non-flat origami states and (2) sets of facets …

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Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau Dec 2018

Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau

Theses and Dissertations

Human knee kinematics, especially during gait, are an important analysis tool. The current "gold standard" for kinematics measurement is a multi-camera, marker-based motion capture system with 3D position tracking. These systems are accurate but expensive and their use is limited to a confined laboratory environment. High deflection strain gauges (HDSG) are a novel class of sensors that have the potential to measure kinematics and can be inexpensive, low profile, and are not limited to measurements within a calibrated volume. However, many HDSG sensors can have a non-linear and non-monotonic response. This thesis explores using a nanocomposite HDSG sensor system for …

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Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick Dec 2018

Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick

Theses and Dissertations

Metallic glass matrix composites (MGMCs) have been developed to improve upon the ductility of monolithic metallic glass. These composites utilize a secondary crystalline phase that is grown into an amorphous matrix as isolated dendritic trees. This work seeks to understand the mechanisms underlying strain delocalization in MGMCs in order to better direct efforts for continual progress in this class of material. A mesoscale modelling technique based on shear transformation zone (STZ) dynamics is used to do so. STZ dynamics is a coarse grained technique that can provide insight into the microscopic processes that control macroscopic behavior, but which can be …

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Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor Dec 2018

Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor

Theses and Dissertations

Developing lifelike vocal fold models is challenging due to various associatedbiomechanical complexities. Nevertheless, the development and analysis of improved vocal foldmodels is worthwhile since they are valuable tools for gaining insight into human vocal foldvibratory, aerodynamic, and acoustic response characteristics. This thesis seeks to contribute tothe development of computational and physical vocal fold modeling in two ways. First is byintroducing a method of obtaining internal deformation fields within vibrating synthetic vocal foldmodels; second is by presenting an optimization algorithm coupled with a computational vocalfold model to optimize geometry and stiffness of a synthetic vocal fold model to achieve morerealistic vibration …

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Using Non-Destructive Testing To Predict Bending Modulus Of Carbon Infiltrated-Carbon Nanotubes, Fred Stile Fagergren Dec 2018

Using Non-Destructive Testing To Predict Bending Modulus Of Carbon Infiltrated-Carbon Nanotubes, Fred Stile Fagergren

Theses and Dissertations

Fabrication of carbon infiltrated carbon nanotubes (CI-CNT) can result in large mechanical property variation, and methods to characterize properties usually involve destructive testing. Finding a non-destructive way to test for stiffness of this material reduces the number of parts that have to be made. It also simplifies testing of complex parts. The stiffness of CI-CNT beams is related to the type of carbon material infiltrated between the carbon nanotubes (CNTs), how it interacts with the CNTs, and how much of it there is. The amount of material can be estimated using the density of the beam, and both the type …

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5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj Dec 2018

5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj

Theses and Dissertations

Knowledge of the full 5-degree Grain Boundary Character Distribution (GBCD) is vital to understanding properties, such as gas diffusivity, that are dominated by grain boundary character. Surface characterization techniques, such as Electron Backscattered diffraction (EBSD), can provide only 4 of the 5 GB characteristics (the rotation between the neighboring grains, and the trace of the GB on the surface). The inclination of the GB in the direction normal to the surface is not known. A previous study indicated that the GB inclination could be recovered by correlating the Electron Backscattered patterns (EBSPs) of sample points near the GB with EBSPs …

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Wall Shear Stress In Simplified And Scanned Avian Respiratory Airways, Michael Sterling Farnsworth Dec 2018

Wall Shear Stress In Simplified And Scanned Avian Respiratory Airways, Michael Sterling Farnsworth

Theses and Dissertations

Birds uniquely produce sound through a vocal organ known as a syrinx. The presence of wall shear stress acting on the airway cells of any organism will affect how airway cells develop and multiply. Unique features of avian airway geometry and breathing pattern might have contributed to the development of the syrinx. This thesis examines wall shear stress in the trachea and first bronchi of avian geometries using computational fluid dynamics. The computational fluid dynamic simulations underwent grid- and time-independence studies and were validated using particle image velocimetry. Parameters such as bird size, bronchial branching angle, and breathing waveform were …

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Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore Nov 2018

Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore

Theses and Dissertations

While vertical takeoff and landing aircraft show promise for urban air transport, distributed electric propulsion on existing aircraft may offer an immediately implementable alternative. Dis- tributed electric propulsion has the potential of increasing the aircraft thrust-to-weight ratio and lift coefficient high enough to enable takeoff distances of less than 100 meters. While fuel based propulsion technologies generally increase in specific power with increasing size, electric propul- sion typically can be decreased in size without a decrease in specific power. The smaller but highly power-dense propulsion units enable alternative designs including many small units, optionally powered units, and vectored thrust from …

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An Experiment To Study The Gaseous Emissions Of A Gas Turbine Operated With Biodiesel As Fuel, David Lee Rochelle Nov 2018

An Experiment To Study The Gaseous Emissions Of A Gas Turbine Operated With Biodiesel As Fuel, David Lee Rochelle

Theses and Dissertations

A continually growing awareness of the finiteness of fossil fuel availability coupled with an ever better understanding of the negative effects of fossil fuel consumption has motivated a search for fuels that can be used in place of fossil fuels, but which can be derived from sustainable sources such as growable organic matter. While much work has been done to understand these substances and apply them on a larger scale (indeed, biodiesel is commonly included in commercially available diesel fuels at fuel pumps); the unique nature of the operating environment for aviation fuels has complicated the application of these substances …

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Experimental Investigation Of Two-Phase (Gas/Liquid) Flow In Intermediate Sized, Horizontal And Inclined Pipes, Noble C. Anumbe Oct 2018

Experimental Investigation Of Two-Phase (Gas/Liquid) Flow In Intermediate Sized, Horizontal And Inclined Pipes, Noble C. Anumbe

Theses and Dissertations

Multiphase flow models and correlations are indispensable tools for the design and operation of vital flow systems that power various industries. The development, validation and tuning of these flow models & correlations depend on the availability of reliable and accurate data. This dissertation reports on an experimental campaign that not only generated crucial two-phase flow data but also evaluated the effect of inclination angle on several flow parameters of interest. The report details the experimental investigation of upward, adiabatic, co-current two-phase (gas/liquid) flow through a 101.6 mm inner diameter (ID) pipe. Experimental data for the investigation were acquired using an …

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Topological Conduction And Investigation On Multi Occurrence Of Dirac Cone, Mustahseen Mobashwer Indaleeb Oct 2018

Topological Conduction And Investigation On Multi Occurrence Of Dirac Cone, Mustahseen Mobashwer Indaleeb

Theses and Dissertations

The unique phenomena in acoustic metamaterial at the Dirac-like cone, and at the exceptional spawning ring could transform the field of engineering with multiple new applications that were never possible before. Localized conical dispersion called Dirac cone at the Brillouin Zone boundaries are the well-known phenomena demonstrated by photonics and phononic metamaterials. However, Dirac cone-like dispersion at the center of the Brillouin zone (where wave number, k = 0) [1] is rare and only happens due to accidental degeneracy at finite frequencies in two-dimensional periodic crystals (PCs), with or without microarchitectures. Accidental degeneracies are generally the ‘sweet spots’ where the …

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