The Effect of Reverse and Opposite Injection on the Film Cooling Performance of a Symmetrical Turbine Blade

A numerical investigation on the film cooling performance of a symmetrical turbine blade is carried out for reverse injection (RH), forward injection (FH), and opposite injection (OH) which combines forward and reverse injection holes. Another objective of this work is to study the effect of the distances between the injection holes, and three different distances are considered. Five configurations are computed for five blowing ratios. A coolant flow is injected through holes inclined at 110 and 70o for reverse and forward jets, respectively. The laterally averaged film cooling effectiveness is obtained using commercial software ANSYS-CFX. In addition, several velocity vectors and contours are presented for analyzing the thermal behavior. The numerical model is based on the Navier–Stokes equations and the Reynolds stress turbulence model (SSG-RSM). The obtained results enable one to choose configurations with high film cooling effectiveness for different blowing ratios.