Aerodynamic Analysis of the Effect of Coolant Crossflow Orientation on Film Cooling: Stereoscopic Particle Image Velocimetry of Cylindrical Film Cooling Holes

Abstract While film cooling is an established cooling technique and a lot of research has been done over the past decades, the large share of studies focus on thermal behavior. Especially experimental data of the aerodynamics, necessary to validate numerical studies and to gain a deeper understanding of the flow interactions and the resulting cooling effects, are still limited. In the present study time-averaged 2D3C stereoscopic particle image velocimetry (SPIV) measurements of film cooling over a flat plate with a high spatial resolution are presented. Cylindrical holes with an inclination angle of 35 deg and a spacing of P/D = 8 are investigated. The used test rig allows operation at enginelike conditions such as realistic density ratios, inflow conditions and blowing ratios. Measurements with different coolant channel orientation (parallel and orthogonal to the hot gas flow), at different coolant Reynolds numbers and varying blowing ratios are performed. A traversable SPIV system is used to capture the whole interaction area of hot gas and the coolant jet. This dataset enables new insights in the aerodynamics of generic film cooling setups, such as the effects of the coolant channel orientation on the flow field and the emerging steady coherent structures.