Improved jet coverage through vortex cancellation

Abstract

In film cooling used in gas turbines, coolant from compressors is introduced to the hot gas stream of the turbine as crossflow jets. The interaction of the coolant jet and crossflow results in the formation of a pair of counter-rotating vortices, or kidney vortices. The sense of rotation of the kidney vortices is such that they exert two indesirable effects : 1) hot air is forced down beneath the jet to the turbine wall, and 2) the vortices tend to lift the jet off the surface by the mutual induction between the vortex pair. We report the potential of promoting jet attachment by weakening the kidney vortices through cancellation.