US 7,351,036 B2 Apr. 1, 2008
* cited by examiner
Primary Examiner—Ninh H. Nguyen
A cooling system for a turbine airfoil of a turbine engine having an elbowed film cooling hole positioned in an outer wall defining the turbine airfoil. The elbowed film cooling hole may include a first section extending from an inner surface of the outer wall into the outer wall, an elbow coupled to the first section in the outer wall, a second section attached to the elbow in the outer wall, and a diffusion slot attached to the second section, having an increasing width moving away from the second section, and extending to an opening in an outer surface of the outer wall. The crosssectional areas of the first section, the elbow and the second section may be substantially equal to meter the flow of cooling fluids through the cooling system to efficiently add to the film cooling layer.
20 Claims, 3 Drawing Sheets