Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Investigation Of Thermal Management And Metamaterials, Calvin T. Roman
Investigation Of Thermal Management And Metamaterials, Calvin T. Roman
Theses and Dissertations
Thermal metamaterials are materials composed of engineered, microscopic structures that exhibit unique thermal performance characteristics based primarily on their physical structures and patterning, rather than just their chemical composition or bulk material properties. The heat transfer performance attributes of a thermal metamaterial are such that similar performance cannot be obtained using conventional materials or compounds. Thermal metamaterials are an emerging technology, and are just now beginning to be acknowledged and developed by the microelectronics and material sciences community. This thesis effort analyzed the current state of thermal metamaterial research, examined the physics and theory of heat transfer and electrical conductivity …
Optimization Of A Low Heat Load Turbine Nozzle Guide Vane, Jamie J. Johnson
Optimization Of A Low Heat Load Turbine Nozzle Guide Vane, Jamie J. Johnson
Theses and Dissertations
Often turbomachinery airfoils are designed with aerodynamic performance foremost in mind rather than component durability. However, future aircraft systems require ever increasing levels of gas-turbine inlet temperature causing the durability and reliability of turbine components to be an ever more important design concern. As a result, the need to provide improved heat transfer prediction and optimization methods presents itself. Here, an effort to design an airfoil with minimized heat load is reported. First, a Reynolds-Averaged Navier-Stokes (RANS) flow solver was validated over different flow regimes as well as varying boundary conditions against extensive data available in literature published by the …
Effects Of Blowing Ratios On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Fu-Jung Chen
Effects Of Blowing Ratios On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Fu-Jung Chen
Theses and Dissertations
The effects of transpiration cooling on heat transfer in the throat region of a porous-walled nozzle were investigated. The experiments were performed in the AFIT low speed shock tube fitted with a Mach 2 nozzle. A blowing region was limited to the area from 1.3 cm prior to the throat to 1.2 cm downstream of the throat. The blowing ratios from -0.0002 (suction) to 0.0117 (blowing) of the main stream flow were studied. Heat flux data were taken from both sides of the nozzle. One side was transpiration cooled by secondary air injection through a porous wall, while the other …
Effects Of Blowing Ratio On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Joseph L. Lenertz
Effects Of Blowing Ratio On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Joseph L. Lenertz
Theses and Dissertations
This experiment analyzed the effects of blowing ratio on heat transfer to the throat region of a porous-walled nozzle, using the AFIT low speed shock tube. Heat flux data were taken from both sides of a two-dimensional Mach 2.0 Re-m=5.2x107 nozzle using thin film resistance thermometers. One side was transpiration-cooled by secondary air injection through a sintered wall, while the other side served as a control. Control results were validated using empirical relations, and cooled side results showed up to a 14% reduction in heat transfer coefficient at blowing ratios of only 0.51%. The linear nature of cooling effectiveness …