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Development Of Novel Passive Control Techniques For More Uniform Temperature At Combustor Exit And Hybrid Les/Rans Modeling, Alka Gupta 2014 University of Wisconsin Milwaukee

Development Of Novel Passive Control Techniques For More Uniform Temperature At Combustor Exit And Hybrid Les/Rans Modeling, Alka Gupta

Theses and Dissertations

Gas turbines have become an important, widespread, and reliable device in the field of power generation. For any gas turbine system, the combustor is an integral part responsible for the combustion of the fuel. A number of studies have shown that the flow field exiting a combustor is highly non-uniform in pressure, velocity and, most importantly, temperature. Hot streaks amongst other non-uniformities cause varying thermal stresses on turbine blades and put pressure on the blade materials. In particular, these non-uniformities can have detrimental effects on the performance of the engine and cause a reduction in the expected life of critical ...


Improved Wind Turbine Control Strategies For Maximizing Power Output And Minimizing Power Flicker, Quan Chen 2014 University of Wisconsin Milwaukee

Improved Wind Turbine Control Strategies For Maximizing Power Output And Minimizing Power Flicker, Quan Chen

Theses and Dissertations

For reducing the cost of energy (COE) for wind power, controls techniques are important for enhancing energy yield, reducing structural load and improving power quality. This thesis presents the control strategies studies for wind turbine both from the perspectives of both maximizing power output and reducing power flicker and structural load,

First, a self-optimizing robust control scheme is developed with the objective of maximizing the power output of a variable speed wind turbine with doubly-fed induction generator (DFIG) operated in Region 2. Wind power generation can be divided into two stages: conversion from aerodynamic power to rotor (mechanical) power and ...


Measurement And Prediction Of The Onset Of Intermittent Dryout During Blowdown Transients For Upward Annular Flow, Bradley A. Statham 2014 McMaster University

Measurement And Prediction Of The Onset Of Intermittent Dryout During Blowdown Transients For Upward Annular Flow, Bradley A. Statham

Open Access Dissertations and Theses

The effect of pressure transients on the onset of intermittent dryout in upward annular flow was experimentally investigated in order to resolve the conflict between the observations drawn from two major data sets in the literature. A delay in time to the onset of dryout at the test section exit relative to the time predicted based on steady-state data was observed in the R-12 experiments of Celata et al (1988; 1991). Steady-state prediction methods were sufficient to predict the upstream progression of a pre-existing dryout front in the water experiments of Lyons and Swinnerton (1983). Steady state and pressure transient ...


Msu Xtreme: Minnesota State University, Mankato's Entry Into The "Clean Snowmobile Challenge 2001", Scott Betcher, Allen Caldwell, Nathan Lindeman, Brian Mandelkow, Dave Maniak, Randy Rohlf, James Skuya, Dennis Swanson, Aaron Wolff, Mark Brandl, Dan Dobesh, Ryan Erickson, Jeff Gillen, Jan Smith, Jason Wilkie 2014 Minnesota State University, Mankato

Msu Xtreme: Minnesota State University, Mankato's Entry Into The "Clean Snowmobile Challenge 2001", Scott Betcher, Allen Caldwell, Nathan Lindeman, Brian Mandelkow, Dave Maniak, Randy Rohlf, James Skuya, Dennis Swanson, Aaron Wolff, Mark Brandl, Dan Dobesh, Ryan Erickson, Jeff Gillen, Jan Smith, Jason Wilkie

Journal of Undergraduate Research at Minnesota State University, Mankato

Minnesota State University, Mankato’s Automotive Engineering Technology program formed a team to enter the Clean Snowmobile Challenge 2001. Selections for the organization’s machine included a 2001 Polaris Edge Chassis specially outfitted with a 2000 500 cc two-stroke Polaris engine. Modifications to the snowmobile were made specifically for Clean Snowmobile Challenge 2001 events. Acceleration, emissions, cold start, noise, fuel economy/range, handling/drivability, hill climb, and static display made up the list of events featured in the competition. MSU Xtreme has modified the snowmobile in every area with special emphasis on emissions and handling. Testing and analysis of the ...


Formula-Sae Wireless Data Logger, Eric Holland 2014 Minnesota State University, Mankato

Formula-Sae Wireless Data Logger, Eric Holland

Journal of Undergraduate Research at Minnesota State University, Mankato

The Formula-SAE (Society of Automotive Engineers) race car requires an onboard data logger to obtain and record the performance information received from the Fuel Injection Controller. This data is needed for analyzing the engine performance of the race car. It is advantageous to have this unit transmit the data via a wireless link to a handheld monitoring tool. Having user interface, like a LCD screen and a keypad, would make the monitoring tool easy to use. Also making the monitoring tool communicate with a PC would offer the beneficial features of saving and printing data. By having the PC connectivity ...


Uncertainty Quantification For A Class Of Mems-Based Vibratory Angular Rate Sensors, Nujhat Abedin 2014 Western University

Uncertainty Quantification For A Class Of Mems-Based Vibratory Angular Rate Sensors, Nujhat Abedin

University of Western Ontario - Electronic Thesis and Dissertation Repository

Numerical schemes that are suitable for predicting response statistics of mass-spring and ring gyroscopes are developed when this class of vibratory gyroscopes are subjected to certain system parameters as well as environment uncertainties. The emphasis is placed on the steady-state part of the response since it is more critical to the operation of a gyroscope. A peak-picking approach which simulates the demodulation process which is used in practice is employed first before applying the Monte Carlo simulation method to predict the response statistics. A number of simulation trials to predict response statistics have been performed for mass-spring and ring-type gyroscopes ...


Numerical Analysis Of Two Phase Flow And Heat Transfer In Condensers, Pooya Mirzabeygi 2014 Western University

Numerical Analysis Of Two Phase Flow And Heat Transfer In Condensers, Pooya Mirzabeygi

University of Western Ontario - Electronic Thesis and Dissertation Repository

Steam surface condensers are commonly used in the power generation industry and their performance significantly affects the efficiency of the power plant. Therefore, it is vital to acquire a better understanding of the complex phenomena occurring inside condensers. A general three-dimensional numerical model is developed in this study to simulate the two-phase flow and heat transfer inside full-scale industrial condensers with irregular tube bundle shapes. The Eulerian-Eulerian two-phase model is selected to simulate gas and liquid flows and the interaction between them. A porous media approach is adopted to model the presence of large number of tubes in the condenser ...


Three Dimensional Transient Asymmetric Flowfields In Physical Vapor Transport, Joseph Dobmeier 2014 Minnesota State University, Mankato

Three Dimensional Transient Asymmetric Flowfields In Physical Vapor Transport, Joseph Dobmeier

Journal of Undergraduate Research at Minnesota State University, Mankato

Physical Vapor Transport is a manufacturing process used to produce single crystals of semiconductor materials such as mercurous chloride (Hg2Cl2). In the past this time-varying process has been studied with numerical simulation by considering three dimensional flow using an axi-symmetric two dimensional model or by restricting the simulation to asymmetric two dimensional flow and dropping the assumption of axi-symmetry from the model. It is generally agreed that neither of these methods accurately represent the true behavior of the process. The purpose of this research was to extend the asymmetric two dimensional model to three dimensions thereby obtaining a solution which ...


Shape Optimization Of Airfoils Without And With Ground Effect Using A Multi-Objective Genetic Algorithm, Yilei He 2014 Washington University in St. Louis

Shape Optimization Of Airfoils Without And With Ground Effect Using A Multi-Objective Genetic Algorithm, Yilei He

Engineering and Applied Science Theses & Dissertations

The focus of this thesis is on shape optimization using a genetic algorithm. A multi-objective genetic algorithm (MOGA) is employed to optimize the shape of an airfoil to improve its lift and drag characteristics, in particular to achieve two objectives simultaneously that is to increase its lift as well as its lift to drag ratio. The commercially available software FLUENT is employed to calculate the flow field on an adaptive structured mesh, which is generated by the commercial mesh generating software ICEM. The flow field is calculated using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a two equation k-ω ...


Fluid Powered Miniature In-Vivo Robots For Minimally Invasive Surgery (Mis), Abolfazl Pourghodrat 2014 University of Nebraska - Lincoln

Fluid Powered Miniature In-Vivo Robots For Minimally Invasive Surgery (Mis), Abolfazl Pourghodrat

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Minimizing the invasiveness of surgery is believed to improve patient outcomes. Bleeding, infection, and pain are major concerns in surgery afflicting patients for decades. Minimally invasive techniques have come into play to reduce these concerns and smooth the evolution of abdominal surgery to a scarless process where nearly all surgeries can be performed without a skin incision. Technology continually advances the frontier of development of novel surgical devices to implement less invasive surgical techniques.

Fusion of robotics and Minimally Invasive Surgery (MIS) has created new opportunities to develop diagnostic and therapeutic tools. Surgical robotics is advancing from externally actuated systems ...


Foss Big Data Storage Solution, nurdeen salami 2014 California Polytechnic State University

Foss Big Data Storage Solution, Nurdeen Salami

STEM Teacher and Researcher (STAR) Program Posters

NASA projects require a reliable approach to store large volumes of data. Accordingly, it is crucial to adopt a lightweight, reliable, and scalable database. Current NASA databases bear costly license fees with undesirable speed and flexibility. The purpose of utilizing the AERO Institute as an IT test bed, or “Sandbox,” is to design, build, test, and implement software solutions prior to transfer to NASA projects. Cassandra coupled with the Astyanax API is a viable solution for storing big data. Store a minimum of 2GB of C-FOSS data in multiple file formats (.csv, .log, .xml, and .jpg). Use benchmark tests to ...


Space Race: Capturing An Orbiting Sample And A Nation’S Imagination, Stephanie La Liberte, Andrew Chavarin, Shubham Gogna, C. Daniel Thomas, Vy Phung, Gabriel Udomkesmalee 2014 California Polytechnic State University

Space Race: Capturing An Orbiting Sample And A Nation’S Imagination, Stephanie La Liberte, Andrew Chavarin, Shubham Gogna, C. Daniel Thomas, Vy Phung, Gabriel Udomkesmalee

STEM Teacher and Researcher (STAR) Program Posters

A proposed architecture for future planetary sample return missions would consist of capturing on-orbit a sample container (collected from the surface of a planetary body and launched into space) and transferring the sample container into an earth return/reentry capsule. A challenge to this proposed architecture is integrating space applicable sensor technologies with sufficient capturing devices. While useful technologies on Earth, Earth-related rendezvous/capture technologies, such as magnetic field sensors, sound-based sensors, and Earth orbit-based radios like GPS, are not applicable to space. Inspired by the in-orbit sample capture challenge, NASA JPL has designed the Space Rendezvous And Capture Experiment ...


Carbon Nanotube Powered Regenerative Braking System, Corbin Ross Martin 2014 Northeastern University

Carbon Nanotube Powered Regenerative Braking System, Corbin Ross Martin

Mechanical Engineering Master's Theses

Regenerative braking systems capture kinetic energy and store it for later use, for example as electrochemical energy in a battery or as kinetic energy in a flywheel. There are currently no commercially available regenerative braking systems that convert kinetic energy into elastic strain energy for storage. Although elastically-deformed springs can permit rapid energy storage during braking and rapid energy release during acceleration, springs made of conventional materials do not have high enough energy densities for practical regenerative braking systems in vehicles. In contrast, carbon nanotubes have incredibly high tensile strength and maximum strain, so that they offer the potential for ...


Influence Of Viscosity Gradient On Bubble Formation At A Submerged Orifice, Leily Majidi 2014 Northeastern University

Influence Of Viscosity Gradient On Bubble Formation At A Submerged Orifice, Leily Majidi

Mechanical Engineering Master's Theses

The objective of the present work was to experimentally investigate bubble formation in different viscosities of Silicone oil. The purpose of these experiments was to try to understand how the shape of the bubbles, formed from a small lower orifice, is affected by aspects of viscosity. The two major directions of investigation involved bubble formation in (i) single and finite liquid layers of varying viscosity and (ii) multiple layers of varying viscosities, to create a viscosity gradient. The experiments were inspired by recent observations of Focused Ion Beam FIB movies of thermal sprayed obsidian splats, in which different elongated `frozen ...


Increased Span Length For The Mgs Long-Span Guardrail System, Nicholas A. Weiland 2014 University of Nebraska - Lincoln

Increased Span Length For The Mgs Long-Span Guardrail System, Nicholas A. Weiland

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Long-span guardrail systems have been recognized as an effective means of shielding low-fill culverts while minimizing construction efforts and limiting culvert damage and repair. The current MGS long-span design provided the capability to span unsupported lengths up to 25 ft (7.6 m) without the use of nested guardrail. The excellent performance of the MGS long-span system in full-scale crash tests suggested that longer span lengths may be possible with the current design.

A detailed analysis of the MGS long-span guardrail system was performed using the finite element software program LS-DYNA®. It was shown that the MGS long-span design had ...


Influence Of Approach Flow Conditions On Urban Street Canyon Flow, Karin Blackman 2014 Western University

Influence Of Approach Flow Conditions On Urban Street Canyon Flow, Karin Blackman

University of Western Ontario - Electronic Thesis and Dissertation Repository

The turbulent flow within a street canyon and the approaching boundary layer has been studied using idealized wind tunnel models and a semi-idealized field experiment conducted in Nantes, France. The effect of upstream roughness on street canyon flow (lateral length/height, L/h = 30) using either 3D (cube) or 2D (rectangular block) upstream roughness, of the same height as the canyon, has been studied for two streamwise canyon width to height aspect ratios (AR) of 1 and 3 using Particle Image Velocimetry. A further wind tunnel model of equivalent geometry to the field experiment was used to compare with flow ...


Understanding The Effects Of Blast Wave On The Intracranial Pressure And Traumatic Brain Injury In Rodents And Humans Using Experimental Shock Tube And Numerical Simulations, Aravind Sundaramurthy 2014 University of Nebraska - Lincoln

Understanding The Effects Of Blast Wave On The Intracranial Pressure And Traumatic Brain Injury In Rodents And Humans Using Experimental Shock Tube And Numerical Simulations, Aravind Sundaramurthy

Engineering Mechanics Dissertations & Theses

Blast induced neurotrauma (BINT) has been designated as the “signature injury” to warfighters in the recent military conflicts. In the past decade, conflicts in Iraq (operation Iraqi freedom) and Afghanistan (operation enduring freedom) as well as the increasing burden of the terrorism around the world resulted in an increased number of cases with blast Traumatic Brain Injury (bTBI). Recently, a lot of research has been done to study the neurological and neurochemical degenerations resulting from BINT using animal models especially rat models. However, it is not clear how and whether the biological outcomes from animal models can be translated to ...


A Cfd Assisted Control System Design For Supercritical Water Cooled Reactor, Rohit V. Maitri 2014 Western University

A Cfd Assisted Control System Design For Supercritical Water Cooled Reactor, Rohit V. Maitri

University of Western Ontario - Electronic Thesis and Dissertation Repository

In this study, the methodology to construct a control system based on computational fluid dynamics (CFD) simulations is developed for supercritical water cooled reactor (SCWR). The CFD model using Reynolds Stress Model (RSM) and k-w SST model is validated with the experimental cases of steady state and vertically up flowing supercritical water in circular tubes for normal heat transfer and deteriorated heat transfer (DHT) cases. This model is extended to simulate the transient thermal-hydraulic behaviour of supercritical fluid flow and heat transfer, and the results are also compared with the 1-D numerical model, THRUST. The DHT phenomenon is investigated using ...


Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson 2014 University of Nebraska - Lincoln

Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson

Mechanical & Materials Engineering Faculty Publications

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further ...


Vehicle Multi-Pass Rut Volume And Mobility Power Study, William W. Barbour 2014 University of Tennessee, Knoxville

Vehicle Multi-Pass Rut Volume And Mobility Power Study, William W. Barbour

Pursuit - The Journal of Undergraduate Research at the University of Tennessee

This paper presents the relationship between applied power by a wheeled vehicle to soil and the rutting effects. Specifically, a strong positive relationship was found between cumulative applied power and total rut volume across multiple passes by the vehicle over the same tracks. Field-testing was conducted using a high-mobility multi-purpose wheeled vehicle (HMMWV) and two distinct soil types. Sensors on the vehicle measured torque and angular velocity of each of the four wheels, from which applied power was calculated. A rut profile meter was used to document the shape of the rut after set numbers of passes and this profile ...


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