Experimental Study of Film Cooling Performance on Turbine Guide Vane with Optimized Hole Arrangements in a Transonic Annular Sector Cascade

摘要

The present study investigated the film cooling performance on the pressure side surface of the nozzle guide vane with the optimized film cooling hole arrangement. An annular sector transonic turbine cascade test facility in Korea Aerospace Research Institute was used. The mainstream and the secondary air for cooling are supplied by 500hp and 50hp compressors, respectively. To measure the film cooling effectiveness on the surface, a transient measurement method was used with the FLIR infrared camera system and the mainstream temperature was maintained 15 to 20°C above the secondary flow temperature using 300kW heater. Five nozzle guide vanes were installed in the test section. The configuration with the cooling hole arrangement proposed by the optimization procedure was tested and compared with the baseline configuration. For the cooling hole arrangement optimization, nine design variables are taken into account for a single objective function of film cooling effectiveness on the pressure side surface. Design of Experiment, Kriging surrogate model and Genetic Algorithm are used for the optimization. The tests were conducted at the mainstream exit Reynolds number based on the chord of 2.2×10~6 and the total coolant mass flow rate was set to be 10% of the inlet main flow. The flow periodicity in the cascade passage was ensured by the surface static pressure measurements. The results showed that considerable improvement of the film cooling effectiveness is observed in the whole region with the optimized configuration, which gives the possibility of coolant mass flow reduction.