Investigation of film cooling on model turbine blade leading edge using DES and LES approaches

The present paper investigates turbulent flow of film cooling on model turbine blade leading edge using two scale-resolving attitude of turbulent flow modeling. In the first attitude the detached eddy simulation (DES) approach based on Spalart-Allmaras and in the second attitude the large eddy simulation (LES) approach will be used. Results show that the DES approach due to its hybrid nature and applying RANS models in near walls, predicts the Fluctuations of spanwise direction in coolant pipe lower. As a result, the coolant flow imports to the main flow with lower turbulence. Also DES approach predicts less turbulent kinetic energy lateral distribution and further turbulent heat flux in near walls. So, in DES approach the adiabatic effectiveness on turbine blade leading edge predicted lower than LES approach and experimental data. In addition, results show that mixture of coolant jet and mainstream hot gas in DES approach is estimated lower than LES approach. In total, it can be deducted that although DES approach provides acceptable results in far wall region, but in near wall region it has problems in correct prediction of turbulence Specifications. In addition, the main advantage of DES approach in comparison with LES approach is 40% reduction of computational cost that can explain using this approach.