ADIABATIC EFFECTIVENESS ON THE SUCTION SIDE OF A TURBINE VANE AND THE EFFECTS OF CURVATURE AT THE POINT OF FILM INJECTION

The effects on film cooling performance due to the use of angled slots with impinging cylindrical holes were studied on the suction side of a scaled-up turbine vane. Various configurations were explored to fully characterize the effects of varying the depth of the slot and the pitch between the impinging feed holes within the slot. Experiments were also conducted to evaluate the effect of local curvature at the point of coolant injection. Each test was conducted with and without an upstream boundary layer trip to determine the effects of changing the approach boundary layer. Rows of discrete round and shaped holes were tested for comparison with the slots. The study of varying slot geometries showed that increasing the depth of the slot and decreasing the pitch between the impinging cylindrical holes enhanced film cooling effectiveness. The optimum slot configuration was found to have comparable adiabatic effectiveness with the better shaped holes configuration at lower blowing ratios, and superior performance at higher blowing ratios. The results pertaining to the local curvature and approach flow showed a significant effect on the round hole performance, but had negligible effect on the angled slot and shaped hole configurations.Copyright © 2008 by ASME