Patent attributes
A turbine airfoil with a plurality of film cooling holes having a diffuser having both stream-wise and spanwise expansion of the cooling air flow. The diffuser is formed from a series of ellipses with a gradual increase in the cross sectional areas in the flow direction. The diffuser has a stream-wise surface of continuous curvature of about 7 degrees, and both the spanwise outward surface and the spanwise inward surface has a continuous curvature of about 7 degrees. The upstream side surface of the diffuser is formed substantially along a straight line. The ellipse shaped diffuser has spanwise and stream-wise curved surfaces such that at the hole opening onto the airfoil wall, the hole has an elliptical cross sectional shape with the major axis in the spanwise direction of the airfoil.
