Prediction of Heat Transfer and Film Cooling on Blade Platform With Stator-Rotor Purge Flow in a 1-1/2 Turbine Stage

Heat transfer and film cooling on a platform from stator-rotor platform purge flow were numerically investigated in a 1-1/2 turbine stage. The effects of coolant mass flow ratio, coolant-to-mainstream density ratio and rotating speed were examined in detail. The results show that higher mass flow rates and density ratios could enhance heat transfer level in the upstream region and the downstream area of the passage vortex lift-off line on the platform, but slightly affected film cooling distributions, particularly in the downstream area. In addition, increasing rotating speed reduced heat transfer over the platform surface. Higher rotating speeds could suppress the passage vortex, but had little effect on film coolant coverage.