A hybrid LES-RANS validation of effusion cooling array measurements

In this work, an effusion cooling array is studied using a hybrid LES-RANS approach under combustor representative conditions. The surface adiabatic cooling effectiveness is examined. Promising results are obtained from the hybrid LES approach based on an 18-million-cell grid. The turbulent flow field is studied in order to investigate the effects on the coolantmainstream mixing, as well as the distribution of the coolant film. It is found that the freestream turbulence leads to early breakdown of the coolant jets at the 1st and 2nd row of coolant holes, while such effects diminish in the downstream region due to the turbulent structures in the mixed mainstream. As a result, the surface adiabatic cooling effectiveness stays low in the first few rows, but keeps growing and reaches a high value in the downstream rows.