Shock cancellation mechanism for the control of unsteady interaction in contra-rotating high- and low-pressure turbines

Abstract

In a high pressure turbine used in combination with a contra-rotating low pressure turbine, in which the geometry of the inlet guide vane of the low pressure turbine induces a reflection of the incident shock wave from the high pressure turbine airfoil that propagates back upstream to impact the blade thereby denigrating both the performance of the high pressure turbine and its durability. The shock wave reflection is eliminated by fitting the downstream vanes with holes or indentations that allow jets of compressor bleed air to penetrate the boundary layer and induce a net velocity component across the main-flow direction in the near-wall region. This induced flow component acts to cancel the net flow component created by the moving shock from the upstream blade row thereby obviating the reflection that occurs naturally to cancel the flow.

Dependencies are inferred from the claim text.