A Numerical Study on Improving Large Angle Film Cooling Performance through the Use of Sister Holes

Abstract

The present study evaluates a novel sister hole cooling technique using large inclination angle cylindrical holes simulated numerically. Here, a 55° inclination angle has been applied to simulate more realistic turbine conditions. Two sister holes bound the primary injection hole and are shifted slightly downstream to promote flow adhesion. As a means of determining the validity of the technique, adiabatic effectiveness and vortex flow structures were evaluated at four blowing ratios: 0.2, 0.5, 1.0, and 1.5. The results indicate that the sister hole technique dramatically reduces the primary kidney vortex pair offering significant improvements in effectiveness at all blowing ratios.

The authors would like to thank the Natural Science and Engineering Research Council of Canada and the Government of Ontario for their support in funding this research. Additional thanks also go out to the High Performance Computing Virtual Laboratory for their funding support as well as their tremendous resources.