Investigation of Film Cooling Using Time-Resolved Stereo Particle Image Velocimetry

In the present study, an existing test rig at the Institute of Thermal Turbomachinery (ITS), Karlsruhe Institute of Technology (KIT), designed for generic film cooling studies is adopted to accommodate time-resolved stereoscopic particle image velocimetry (SPIV) measurements. Through a similarity analysis, the test rig geometry is scaled by a factor of about 20. Operating conditions of hot gas and cooling air inlet and exit can be imposed that are compliant with realistic engine conditions including density ratio (DR). The cooling air is supplied by a parallel-to-hot gas coolant flow-configuration with a coolant Reynolds number of 30, 000. Time-resolved and time-averaged stereo article image velocimetry data for a film cooling flow at high DR and a range of blowing ratios are presented in this study. The investigated film cooling hole constitutes a 10 deg–10 deg–10 deg laidback fan-shaped hole with a wide spacing of P/D = 8 to insure the absence of jet interaction. The inclination angle amounts to 35 deg. The time-resolved data indicate transient behavior of the film cooling jet.