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 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. 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 investigated film cooling hole constitutes a 10°-10°-10° 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°. The time-resolved data indicates transient behaviour of the film cooling jet.

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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 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. 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 investigated film cooling hole constitutes a 10o-10o-10o 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°. The time-resolved data indicates transient behaviour of the film cooling jet.

Cyclone cooling is a promising method for a more effective internal cooling of turbine rotor blades with simplified internal channels including a swirling flow to enhance internal heat transfer. Previous studies have led to the conclusion that improving the cooling performance requires an adapted film cooling design, tailored to the cyclone cooling application. In this paper, a turbine rotor blade with realistic, complex features including the cyclone cooling design is investigated experimentally using infrared thermography to capture surface temperature. The objective is to analyze the influence of increased film cooling hole diameter on a cyclone-cooled blade’s surface temperature. For this purpose, the diameter of the holes at the blade’s leading edge, which are fed by the cyclone channel, is increased. The tests are performed for different coolant mass flow rates and swirl numbers. Additionally, CFD simulations are performed to analyze the aerodynamics of the cooling air. The test results show that the surface temperature at the leading edge can be decreased by increasing the diameter of the film cooling holes, however, adversely affecting the remaining blade surface. This can be explained by a redistribution of the supplied coolant. The increase of cooling effectiveness at the leading edge is at the highest when a low swirl is generated.

Numerous experimental investigations, predominantly determining the adiabatic film cooling effectiveness and the heat transfer coefficient with film cooling dependent on parameters such as blowing ratio (M), density ratio (DR), velocity ratio (VR) and momentum flux ratio (IR) have been conducted in the past for a vast variety of geometries. To fully characterize a jet in cross-flow for its application in film cooling, thermal and aerodynamic parameters have to be analysed in conjunction. In the present work, detailed flow field measurements using Stereoscopic Particle Image Velocimetry (SPIV) are conducted at engine-realistic operating conditions in a test rig at the Institute of Thermal Turbomachinery (ITS) at the Karlsruhe Institute of Technology (KIT). Additionally, thermal measurements using Infrared Thermography (IRT) are carried out to determine the adiabatic film cooling effectiveness and the heat transfer coefficient with film cooling. Two film cooling hole geometries are analysed: A 10°-10°-10° laidback fan-shaped shaped film cooling hole (LFH10) and a slot geometry with a plenum-like inlet. Flow field data, and thermal film cooling quantities are analysed to quantify and characterize their aerothermal behaviour. The significance of the stability and continuity of the exiting film cooling jets for the thermal performance is demonstrated to comprehend the differences in how efficiently the provided cooling air is used. It is shown, that the absence of the counter-rotating vortex pair may not necessarily lead to an improved adiabatic film cooling effectiveness ηa,W.