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Design And Manipulation Of A Power-Generating System With High-Temperature Fuel Cells For Hypersonic Applications, Jack Randolph Chalker
Design And Manipulation Of A Power-Generating System With High-Temperature Fuel Cells For Hypersonic Applications, Jack Randolph Chalker
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Current hypersonic vehicles tend to be incapable of producing onboard power with traditional generators due to their use of supersonic combusting ramjets (scramjets). Because of this, they seek additional energy sources for supporting advanced electronics or other auxiliary power-dependent devices while requiring elaborate thermal management systems to combat temperatures exceeding 700ºC. The incorporation of Solid Oxide Fuel Cell (SOFCs) stacks is an efficient solution, capable of generating large quantities of power through the use of natural fuel sources at high temperatures. Developments in this thesis include the design, construction, and support of a system operating at hypersonic-environment conditions with a …
Design And Implementation Of Periodic Unsteadiness Generator For Turbine Secondary Flow Studies, Nathan James Fletcher
Design And Implementation Of Periodic Unsteadiness Generator For Turbine Secondary Flow Studies, Nathan James Fletcher
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A primary source of periodic unsteadiness in low-pressure turbines is the wakes shed from upstream blade rows due to the relative motion between adjacent stators and rotors. These periodic perturbations can affect boundary layer transition, secondary flow, and loss generation. In particular, for high-lift front-loaded blades, the secondary flowfield is characterized by strong three-dimensional vortical structures. It is important to understand how these flow features respond to periodic disturbances. A novel approach was taken to generate periodic unsteadiness which captures some of the physics of turbomachinery wakes. Using stationary pneumatic devices, pulsed jets were used to generate disturbances characterized by …
Blended Wing Design Considerations For A Next Generation Commercial Aircraft, Jay Abhilash Vora
Blended Wing Design Considerations For A Next Generation Commercial Aircraft, Jay Abhilash Vora
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The current aircraft design has not changed significantly in the last few decades. Growing environmental concerns and fuel prices are driving manufacturers to develop unconventional but efficient aircraft configurations. The blended wing body (BWB) configuration provides an alternate and more efficient means of subsonic travel. The BWB aircraft replaces the traditional wings and fuselage with hybrid wing shape where the fuselage and wings have integrated. Major aircraft manufacturers are researching the BWB concept incorporating electric propulsion for civil transport use. In this research a 300 passenger BWB aircraft aerodynamic shape is designed. This aircraft is used to assess the aerodynamic …
As-Manufactured Modeling Of A Mistuned Turbine Engine Compressor Evaluated Against Experimental Approaches, Daniel L. Gillaugh
As-Manufactured Modeling Of A Mistuned Turbine Engine Compressor Evaluated Against Experimental Approaches, Daniel L. Gillaugh
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As-manufactured rotors behave quite differently than nominal, as-designed rotors due to small geometric and material property deviations in the rotor, referred to as mistuning. Traditional integrally bladed rotor (IBR) modeling approaches assume each blade is identical. State-of-the-art IBR dynamic response predictions can be accomplished using asmanufactured models (AMM) generated via optical topography measurements and mesh morphing. As-manufactured models account for geometric deviations occurring through the machining process, material deviations and field wear, allowing each blade to respond differently. Rotor designs are intended to avoid resonance crossings throughout an engine’s operating range, but total avoidance is challenging. This has led to …
Aerodynamics Of Fan Blade Blending, Clint J. Knape
Aerodynamics Of Fan Blade Blending, Clint J. Knape
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Blending is a method of fan and compressor blade repair. The goal of the blending process is to remove stress concentration points such as cracks and nicks along the leading, trailing, or tip edges of the blade. The stressed areas are typically removed by grinding or cropping away the surrounding material. For integrally bladed rotor (IBR) disks, repairing a damaged blade is much more economical than replacing the entire disk. However, the change in shape of the blade will change the local aerodynamics and result in mistuning, both structurally and aerodynamically. In a worst case scenario, the change in the …
Using Cfd To Improve Off-Design Throughflow Analysis, Troy J. Lanchman
Using Cfd To Improve Off-Design Throughflow Analysis, Troy J. Lanchman
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In turbomachinery design, complex internal flows give rise to significant losses and blockage whose effects are difficult to properly analyze without detailed computational fluid dynamics (CFD) methods or experiments. In a typical design method, CFD is used in conjunction with simpler throughflow or cascade codes to hasten the process. However, the lesser physical accuracy of the design codes demands the inclusion of models to improve the accuracy of the throughflow codes. This thesis aims to use CFD data to generate improved loss and blockage models for a 2D compressor throughflow code by matching throughflow data to CFD data using optimizations. …
Power/Thermal Interaction Within An Adaptive Turbine Engine, Andrew K. Desomma
Power/Thermal Interaction Within An Adaptive Turbine Engine, Andrew K. Desomma
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Usually power take off (PTO) with a two-spool turbofan engine has been accomplished via the high pressure (HP) shaft and bleed air from the high-pressure compressor (HPC). The PTO is used to run various aircraft components such as generators and hydraulic pumps, which also produce waste heat. To better understand the coupled transient nature of balancing engine thrust, power take off and thermal management, a transient variable cycle three stream turbofan engine model has been developed to investigate the integrated behavior. The model incorporates many dynamic features including a third-stream heat exchanger as a heat sink for thermal management and …