Airfoil with plasma generator for shielding a boundary layer upstream of a film cooling hole and corresponding operating method

摘要

An upstream plasma boundary layer shielding system (11) includes film cooling apertures (49) disposed through a wall (26) having cold and hot surfaces and angled in a downstream direction (D) from a cold surface (59) of the wall (26) to an outer hot surface (54) of the wall (26). A plasma generator (2) located upstream (U) of the film cooling apertures (49) is used for producing a plasma (90) extending downstream over the film cooling apertures (49). Each plasma generator (2) includes inner and outer electrodes (3, 4) separated by a dielectric material (5) disposed within a groove (6) in the outer hot surface (54). The wall (26) may be part of a hollow airfoil (39) or an annular combustor or exhaust liner. A method for operating the upstream plasma boundary layer shielding system (11) includes forming a plasma (90) extending in the downstream direction (D) over the film cooling apertures (49) along the outer hot surface (54) of the wall (26). The method may further include operating the plasma generator (2) in steady state or unsteady modes.