US Patent 8152467 Blade with tangential jet generation on the profile

A blade of a fluid-flow machine has at least one cavity 2 arranged in the blade 1, with the cavity 2 connecting to a fluid supply, and at least one outlet opening 3 connecting the cavity 2 to a flow path, in which the blade 1 is arranged. The outlet opening 3 is of a nozzle-type design and essentially inclined in a direction of a main flow extending longitudinally to a corresponding surface of the blade 1. The outlet opening 3 extends over at least a part of the blade 1 height and the outlet opening 3 forms a step in a contour of the blade 1 profile, with a fluid jet issuing from the outlet opening 3 essentially tangentially attaching onto the blade surface.