Numerical study on discharge coefficients of a jet in crossflow

Discharge coefficient, C_d is a crucial parameter for film cooling. In the present work, the effects of various contributing factors on the discharge coefficient of cylindrical holes were studied numerically. Effects of the mainstream Mach number, flow turbulence, shock wave, jet inclination angel and the pressure ratio of the flows were concerned. Comparison against the test data shows the modeling is capable to present accurate solutions for the predicted objective. Results indicate that the pressure fields as well as the velocity distributions above the jets are vulnerable to the change of the above mentioned factors and can further exert impact on the discharge coefficient. An increase in Mach number of the external flow from 0.6 to 1.2 leads to a reduction in discharge coefficient by more than 50%. Smaller inclination angle can weaken the orthogonal interaction between the mainstream and the coolant flow, thus can mitigate the reduction in C_d caused by the high Mach number of the external flow.