US Patent 10422230 Cooling hole with curved metering section

A gas turbine engine component having a cooling hole includes a first wall having a cooling hole inlet, a second wall generally opposite the first wall and having a cooling hole outlet, a metering section extending downstream from the inlet and having a hydraulic diameter (dh), and a diffusing section extending from the metering section to the outlet. The metering section includes a substantially convex first surface extending from a first end to a second end, a substantially concave second surface extending from a third end to a fourth end, and first and second curved portions connecting the ends of the first and second surfaces.