Abstract: It is an object of the invention to provide a film cooling apparatus of increased effectiveness and efficiency. In accordance with the invention, a cooling fluid is injected into a hot flowing gas through a passageway in a wall which contains and is subject to the hot gas. The passageway is slanted in a downstream direction at an acute angle to the wall. A cusp shape is provided in the passageway to generate vortices in the injected cooling fluid thereby reducing the energy extracted from the hot gas for that purpose. The cusp shape increases both film cooling effectiveness and wall area coverage. The cusp may be at either the downstream or upstream side of the passageway, the former substantially eliminating flow separation of the cooling fluid from the wall immediately downstream of the passageway.

Abstract: The object of the invention is to provide more effective film cooling to protect a wall surface from a hot fluid which impinges on or flows along the surface. A film of cooling fluid having increased area is provided by changing the direction of a stream of cooling fluid through an angle of from 135.degree. to 165.degree. before injecting it through the wall into the hot flowing gas.As shown in FIG. 1, cooling fluid is injected from an orifice (16) through a wall (10) into a hot flowing gas (11) at an angle (20) to form a cooling fluid film (12). Cooling fluid is supplied to the orifice (16) from a cooling fluid source (13) via a turbulence control passageway (14) having a curved portion (18) between two straight portions (17 and 19).The angle (24) through which the direction of the cooling fluid is turned results in less mixing of the cooling fluid with the hot gas (11), thereby substantially increasing the length of the film (12) in a downstream direction.FIGS.