Abstract: A flow directing assembly for use in a turbine engine comprising: a plurality of circumferentially spaced blades, each of the blades including a radial projecting airfoil with a concave pressure side and a convex suction side that extend from a platform; and a plurality of flow passages, each flow passage defined by the airfoils of neighboring blades and an inner wall formed by abutting platforms of neighboring blades, the inner wall forming the inner radial boundary of the flow passage; wherein the inner wall of one or more of the flow passages comprises means for reducing frictional losses between the flow through the turbine engine and the inner wall. The means for reducing frictional losses may comprise a non-axisymmetrical trough positioned between neighboring airfoils that is configured to reduce frictional losses.

Abstract: A flow directing assembly for use in a turbine engine comprising: a plurality of circumferentially spaced blades, each of the blades including a radial projecting airfoil with a concave pressure side and a convex suction side that extend from a platform; and a plurality of flow passages, each flow passage defined by the airfoils of neighboring blades and an inner wall formed by abutting platforms of neighboring blades, the inner wall forming the inner radial boundary of the flow passage; wherein the inner wall of one or more of the flow passages comprises means for reducing frictional losses between the flow through the turbine engine and the inner wall. The means for reducing frictional losses may comprise a non-axisymmetrical trough positioned between neighboring airfoils that is configured to reduce frictional losses.