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 Technol-
ogy (KIT) designed for generic film cooling studies is adopted
to accommodate time resolved stereoscopic particle image ve-
locimetry measurements. Through a similarity analysis the test
rig geometry is scaled by a factor of about 20. Operating con-
ditions of hot gas and cooling air inlet and exit can be imposed
that are compliant with realistic engine conditions including den-
sity ratio. 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 particle image
velocimetry data for a film cooling flow at high density ratio and
a range of blowing ratios is presented in this study. The inves-
tigated film cooling hole constitutes a 10◦-10◦-10◦ laidback fan-
shaped hole with a wide spacing of P/D = 8 to insure the ab-
sence of jet interaction. The inclination angle amounts to 35◦.
The time-resolved data indicates transient behaviour of the film
cooling jet.