Patent attributes
An airfoil element has first and second ribs each connecting the pressure side and the suction side. Each of the first and second ribs define: a tube portion circumscribing a rib passage; and first and second connector arms joining the tube portion to, respectively, the pressure side and the suction side. The first rib, the second rib, and the airfoil wall bound a continuous cooling channel having a pressure side portion to the pressure side of the mean line and a suction side portion to the suction side of the mean line. At least one of the pressure side portion and the suction side portion includes a skin passageway between at least one of the respective tube portions of the first rib and second rib and an adjacent portion of an interior surface of the airfoil wall. The skin passageway has an outer surface formed by the adjacent portion and an inner surface formed by said at least one of the respective tube portions. At least one of the outer surface and the inner surface has a plurality of protrusions into the skin passageway.
