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Air Force Institute of Technology

Theses and Dissertations

Turbines

Articles 1 - 3 of 3

Full-Text Articles in Mechanical Engineering

Effects Of High Freestream Turbulence And Conduction On Film Cooling Effectiveness Of Shaped Holes, Richard A. Macias Jr. Mar 2020

Effects Of High Freestream Turbulence And Conduction On Film Cooling Effectiveness Of Shaped Holes, Richard A. Macias Jr.

Theses and Dissertations

With technological advancements allowing higher turbine temperatures, film cooling continues to be an important research area. The Film Cooling Rig (FCR) was fitted with a turbulence generator to vary freestream turbulence intensity and length scale, enabling the effects of high freestream turbulence on overall effectiveness to be studied. A cylindrical hole and laidback fan-shaped hole were investigated over a range of Advective Capacity Ratio (ACR) for freestream turbulence intensities of 2%, 10%, and 15%. For a given ACR, increasing the turbulence intensity resulted in lower overall effectiveness values due to the larger heat transfer coefficient that comes from turbulent ow. …


Heat Transfer Due To Unsteady Effects As Investigated In A High-Speed, Full-Scale, Fully-Cooled Turbine Vane And Rotor Stage, Jonathan R. Mason Jun 2008

Heat Transfer Due To Unsteady Effects As Investigated In A High-Speed, Full-Scale, Fully-Cooled Turbine Vane And Rotor Stage, Jonathan R. Mason

Theses and Dissertations

Experiments were conducted to examine the effects of film cooling on a gas turbine engine’s high‐pressure turbine section. The focus for this effort was in the tip/shroud region of a rotor stage and a high pressure turbine vane. A primary goal was to understand the unsteady flow effects. Attempts were also made to characterize the effects as caused by the fully‐cooled rotor stage. Data for this investigation was taken at the U.S. Air Force’s Turbine Research Facility (TRF), a transient blowdown facility with instrumentation fitted to a full‐scale, high‐speed, fully‐cooled vane and rotor stage of proprietary design. Measurements of pressure, …


Optimization Of A Low Heat Load Turbine Nozzle Guide Vane, Jamie J. Johnson Mar 2006

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 …