Blade tip profile

Abstract

An airfoil includes a blade having a leading edge, a trailing edge, a pressure side, a suction side, a tip, and a scoop. The scoop extends along the tip of the blade. The scoop comprises a difference in a radial height of the blade from a pressure side to a suction side of the blade. The radial height of the blade at the pressure side is less than the radial height of the blade at the suction side.

1 . An airfoil comprising:
 a blade having a leading edge, a trailing edge, a pressure side, a suction side, and a tip; and   a scoop extending along the tip of the blade, wherein the scoop comprises a difference in a radial height of the blade from the pressure side to the suction side of the blade, and wherein the radial height of the blade at the pressure side is less than the radial height of the blade at the suction side.   
     
     
         2 . The airfoil of  claim 1 , further comprising a pocket recess opening at a tip of the blade. 
     
     
         3 . The airfoil of  claim 2 , wherein the pocket recess is asymmetric with respect to a camber line of the blade. 
     
     
         4 . The airfoil of  claim 2 , wherein the pocket recess is biased toward one of a suction side or a pressure side of the blade. 
     
     
         5 . The airfoil of  claim 2 , wherein the pocket recess is angled with respect to a camber line of the blade such that a first wall of the blade is thicker adjacent the leading edge than a second wall of the blade. 
     
     
         6 . The airfoil of  claim 1 , wherein the scoop extends from the leading edge to the trailing edge of the blade. 
     
     
         7 . The airfoil of  claim 1 , wherein the difference in radial height between the pressure side and the suction side is greater than or equal to tip clearance and is less than or equal to about 15% of blade span. 
     
     
         8 . The airfoil of  claim 1 , wherein the scoop has a step feature at the tip of the blade, and wherein the step feature comprises a change in radial height between an outer radial surface and an inner radial surface of the tip of the blade. 
     
     
         9 . The airfoil of  claim 8 , wherein the step feature has a fillet radius. 
     
     
         10 . The airfoil of  claim 8 , wherein the step feature extends along a camber line of the blade such that the outer radial surface has substantially a same thickness as the inner radial surface. 
     
     
         11 . The airfoil of  claim 8 , wherein the step feature is asymmetric with respect to a camber line of the blade. 
     
     
         12 . The airfoil of  claim 11 , wherein the step feature is biased toward one of the suction side or the pressure side. 
     
     
         13 . The airfoil of  claim 11 , wherein the step feature is angled with respect to the camber line. 
     
     
         14 . A blade comprising:
 an outer radial surface disposed along a suction side of a tip of the blade;   an inner radial surface disposed along a pressure side of the tip of the blade, the inner radial surface having a different radial height than the outer radial surface; and   a pocket recess opening at the tip and disposed between the inner radial surface and the outer radial surface.   
     
     
         15 . The blade of  claim 14 , wherein the inner radial surface and the outer radial surface extend from a leading edge to a trailing edge of the blade. 
     
     
         16 . The blade of  claim 14 , wherein a transition between the inner radial surface and the outer radial surface occurs along a camber line of the blade such that the outer radial surface has substantially a same thickness as the inner radial surface. 
     
     
         17 . The blade of  claim 14 , wherein a transition between the inner radial surface and the outer radial surface is asymmetric with respect to a camber line of the blade such that the outer radial surface has a different thickness than the inner radial surface. 
     
     
         18 . The blade of  claim 14 , wherein the pocket recess is asymmetric with respect to a camber line of the blade. 
     
     
         19 . The blade of  claim 18 , wherein the pocket recess is biased toward one of a suction side or a pressure side of the blade. 
     
     
         20 . The blade of  claim 18 , wherein the pocket recess is angled with respect to the camber line such that a first wall of the blade is thicker adjacent the leading edge than a second wall of the blade.