Heat Transfer Measurements on the Endwall of a Variable Speed Power Turbine Blade Cascade

Heat transfer measurements were obtained on the planar endwall of a 2-D section of a variable speed power turbine (VSPT) rotor blade in a linear cascade. Infrared thermography was used to determine the endwall heat transfer distribution. Changes in the local heat transfer rates with Reynolds number were used to identify the laminar, turbulent, and transitional flow regimes, as well as to determine regions of flow separation. Steady state data were obtained for six incidence angles ranging from +15.8° to –51.0°, and at five flow conditions for each angle. Reynolds numbers were varied over an order of magnitude while two exit Mach number conditions were examined in order to accommodate the facility operating envelope.