Measurement of unsteady adiabatic film cooling effectivness of a turbine blade with iPSP

Abstract

With the help of iPSP, which measures the partial pressure of oxygen at a surface, it is possible to determine the film cooling effectivness when using an inert (oxygen-free) gas as coolant. Results are shown for a recent experimental measurement campaign in the wind tunnel for straight cascades Göttingen (EGG), whereby the temperature sensitivity of the used iPSP is corrected using Infrared thermography. Using high-powered LEDs and two high speed cameras, it was possible to obtain the film cooling effectivness up to 10000 Hz on almost all of the turbine blade, both on the pressure and the suction side. The results provide valuable insights to the film cooling design of the blade, the effect of flow and cooling parameters on the steady and unsteady film cooling effectivness and a good correlation to numerical simulations could be obtained.