US Patent 10221693 Trench cooling of airfoil structures

An airfoil comprises at least one wall defining a leading edge, a trailing edge, a pressure side extending between the leading edge and the trailing edge, and a suction side extending between the leading edge and the trailing edge. The airfoil is curved in three dimensions and has one or more cavities defined by an interior surface of the at least one wall. A plurality of cooling film holes extending between the cavity and at least one cooling trench located on at least one of the pressure side and the suction side, spaced from the leading edge. The at least one trench has a floor spaced from an outer surface of the airfoil. The plurality of cooling film holes extend through the floor at an angle other than perpendicular.