A New High-Speed Annular Sector Test Rig for Film Cooling Performance Measurements

Effective endwall cooling can be achieved by utilizing design related gaps between turbine components for coolant injection. For dimensioning purposes, it is essential to understand the influence of slot geometry and coolant related parameters on both film cooling effectiveness and heat transfer. To account for the influence of the radial pressure gradient on secondary flow and thus on film cooling performance, an annular sector cascade has been developed and integrated into the high-speed turbine test rig at the Institute of Fluid Machinery and Fluid Dynamics (SAM) of the University of Kaiserslautern-Landau, Germany. The cascade is equipped with four state-of-the-art nozzle guide vanes with axisymmetrically contoured endwalls. An exchangeable insert in the central passage endwall allows different upstream slot geometries to be investigated. It incorporates various measurement techniques such as five-hole probes, pressure sensitive paint and infrared thermography to investigate both thermal and aerodynamic aspects of film cooling.