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Vortex Tilting And The Enhancement Of Spanwise Flow In Flapping Wing Flight, Spencer Frank Dec 2011

Vortex Tilting And The Enhancement Of Spanwise Flow In Flapping Wing Flight, Spencer Frank

HIM 1990-2015

In summary the tilting mechanism helps to explain the overall flow structure and the stability of the leading edge vortex.; The leading edge vortex has been identified as the most critical flow structure for producing lift in flapping wing flight. Its stability depends on the transport of the entrained vorticity into the wake via spanwise flow. This study proposes a hypothesis for the generation and enhancement of spanwise flow based on the chordwise vorticity that results from the tilting of the leading edge vortex and trailing edge vortex. We investigate this phenomenon using dynamically scaled robotic model wings. Two different …


Investigation On Interactions Of Unsteady Wakes And Film Cooling On An Annular Endwall, Matthew J. Golsen Dec 2011

Investigation On Interactions Of Unsteady Wakes And Film Cooling On An Annular Endwall, Matthew J. Golsen

HIM 1990-2015

In recent decades, greater interest in the effect of rotational wakes on gas turbine film cooling applications has produced increasing numbers of studies on these unsteady phenomena. Wakes are primarily shed from upstream components such as transition duct walls, stator vanes, and rotors. Studies have shown that in areas of unsteady flow, the best performing parameters in conventional steady investigations may not be the best for unsteady applications. One common method of modeling the unsteady wake interaction in subsonic flows is the use of spoke wheel type wake generators using cylindrical rods to produce the velocity detriment and local increase …


Context-Driven Agents In Computer Supported Cooperative Works, Brian D. Lichtman Dec 2011

Context-Driven Agents In Computer Supported Cooperative Works, Brian D. Lichtman

HIM 1990-2015

This thesis describes a research project that investigates the level of contextualization needed to successfully build context-driven agents that can manage a cooperative project. Many times in industry, collaborators in a large project may be located vast distances from each other. It is for this reason that management of such projects can often be difficult. The purpose of this research is to design an agent that can take on the role of a project manager (PM) to assist the human project manager. Specifically, this thesis looks to give such project management agents full situational awareness. It is hypothesized that only …


Decolorization Of An Azo And Anthraquinone Textile Dye By A Mixture Of Living And Non-Living Trametes Versicolor Fungus, Christine M. Dykstra May 2011

Decolorization Of An Azo And Anthraquinone Textile Dye By A Mixture Of Living And Non-Living Trametes Versicolor Fungus, Christine M. Dykstra

HIM 1990-2015

Wastewater from the textile industry is difficult to treat effectively due to the prevalent use and wide variety of synthetic dyes that are resistant to conventional treatment methods. White-rot fungi, such as Trametes versicolor, have been found to be effective in decolorizing many of these synthetic dyes and current research is focusing on their application to wastewater treatment. Although numerous studies have been conducted on the ability of both living and nonliving Trametes versicolor to separately decolorize textile dyes, no studies were found to have investigated the use of a mixture of live and dead fungus for decolorization. This study …


Integration Of Communication Constraints Into Physiocomimetic Swarms Via Placement Of Location Based Virtual Particles, Joshua J. Haley May 2011

Integration Of Communication Constraints Into Physiocomimetic Swarms Via Placement Of Location Based Virtual Particles, Joshua J. Haley

HIM 1990-2015

This thesis describes a change to the Physiocomimetics Robotic Swarm Control framework that implements communication constraints into swarm behavior. These constraints are necessary to successfully implement theoretical applications in the real world. We describe the basic background of swarm robotics, the Physiocomimetics framework and methods that have attempted to implement communications constraints into robotic swarms. The Framework is changed by the inclusion of different virtual particles at a global and local scale that only cause a force on swarm elements if those elements are disconnected from a swarm network. The global particles introduced are a point of known connectivity and …


An Experimental And Numerical Study Of Secondary Flows And Film Cooling Effectiveness In A Transonic Cascade, James C. Kullberg May 2011

An Experimental And Numerical Study Of Secondary Flows And Film Cooling Effectiveness In A Transonic Cascade, James C. Kullberg

HIM 1990-2015

Experimental tests on a transonic annular rig are time-consuming and expensive, so it is desirable to use experimental results to validate a computational model which can then be used to extract much more information. The purpose of this work is to create a numerical model that can be used to simulate many different scenarios and then to apply these results to experimental data.; In the modern world, gas turbines are widely used in aircraft propulsion and electricity generation. These applications represent a massive use of energy worldwide, so even a very small increase in efficiency would have a significant beneficial …


Assessing The Viability Of Sol-Gel Nimgo Films For Solar Blind Detection, Amber Scheurer May 2011

Assessing The Viability Of Sol-Gel Nimgo Films For Solar Blind Detection, Amber Scheurer

HIM 1990-2015

Wide bandgap semiconductors have been broadly investigated for their potential to detect and emit high energy ultraviolet (UV) photons. Advancements in deep UV optoelectronic materials would enable the efficient and affordable realization of many medical, industrial and consumer UV optical devices. The traditional growth method, vacuum deposition, is an extremely complicated and expensive process. Sol-gel processing dramatically simplifies facility requirements and can be scaled to industrial size. The work presented here involves a novel study of the ternary wide bandgap material Ni1-xMgxO. Films were developed by sol-gel spin coating for investigation of material and electrical properties. This method produced films …


Effect Of Rib Aspect Ratio On Heat Transfer And Friction In Rectangular Channels, Lucky Vo Tran Jan 2011

Effect Of Rib Aspect Ratio On Heat Transfer And Friction In Rectangular Channels, Lucky Vo Tran

HIM 1990-2015

The heat transfer and friction augmentation in the fully developed portion of a 2:1 aspect ratio rectangular channel with orthogonal ribs at channel Reynolds numbers of 20,000, 30,000, and 40,000 is studied both experimentally and computationally. Ribs are applied to the two opposite wide walls. The rib aspect ratio is varied systematically at 1, 3, and 5, with a constant rib height and constant rib pitch (rib-pitch-to-rib-height ratio of 10). The purpose of the study is to extend the knowledge of the performance of rectangular channels with ribs to include high aspect ratio ribs. The experimental investigation is performed using …


Toward Increasing Performance And Efficiency In Gas Turbines For Power Generation And Aero-Propulsion Unsteady Simulation Of Angled Discrete-Injection Coolant In A Hot Gas Path Crossflow, Perry L. Johnson Jan 2011

Toward Increasing Performance And Efficiency In Gas Turbines For Power Generation And Aero-Propulsion Unsteady Simulation Of Angled Discrete-Injection Coolant In A Hot Gas Path Crossflow, Perry L. Johnson

HIM 1990-2015

This thesis describes the numerical predictions of turbine film cooling interactions using Large Eddy Simulations. In most engineering industrial applications, the Reynolds-Averaged Navier-Stokes equations, usually paired with two-equation models such as k-Greek lowercase letter epsilon] or k-Greek lowercase letter omega], are utilized as an inexpensive method for modeling complex turbulent flows. By resolving the larger, more influential scale of turbulent eddies, the Large Eddy Simulation has been shown to yield a significant increase in accuracy over traditional two-equation RANS models for many engineering flows. In addition, Large Eddy Simulations provide insight into the unsteady characteristics and coherent vortex structures of …


Heat Transfer Study Of A Triple Row Impingement Channel At Large Impingement Heights, Roberto Claretti Jan 2011

Heat Transfer Study Of A Triple Row Impingement Channel At Large Impingement Heights, Roberto Claretti

HIM 1990-2015

Advanced cooling techniques are required to increase the Brayton cycle temperature ratio necessary for the increase of the overall cycle's efficiency. Current turbine components are cooled with an array of internal cooling channels in the midchord section of the blade, pin fin arrays at the trailing edge and impingement channels in the leading edge. Impingement channels provide the designer with high convective coefficients on the target surface. Increasing the heat transfer coefficient of these channels has been a subject of research for the past 20 years. In the current study, a triple row impingement channel is studied with a jet …