Blade or vane of differing roughness and production process

Abstract

A blade or vane of different roughness and a process for producing such a blade or vane are presented. The performance of the blade or vane of a compressor or of a turbine can be improved because of the different configuration of the roughness of the surfaces on the suction side and the pressure side of the blade or vane.

1 . A curved blade or vane, comprising:
 a suction side; and   a pressure side,   wherein the blade or vane comprises a different roughnesses between a surface of the suction side and a surface of the pressure side, and   wherein the surface of the suction side comprises a lesser roughness than the surface of the pressure side.   
     
     
         2 . The blade or vane as claimed in  claim 1 , wherein the blade or vane comprises an uncoated substrate surface, and wherein the different roughnesses are formed on the substrate surface. 
     
     
         3 . The blade or vane as claimed in  claim 1 , wherein a metallic coating is applied to the blade or vane as an outermost layer and comprises the different roughnesses. 
     
     
         4 . The blade or vane as claimed in  claim 1 , wherein a ceramic coating is applied to the blade or vane as an outermost layer and comprises the different roughnesses. 
     
     
         5 . The blade or vane as claimed in  claim 1 , wherein roughness of the surface of the pressure side is at least two times greater than roughness of the surface of the suction side. 
     
     
         6 . The blade or vane as claimed in  claim 1 , wherein roughness of the surface of the pressure side is at least three times greater than roughness of the surface of the suction side. 
     
     
         7 . The blade or vane as claimed in  claim 1 , wherein the surface of the suction side comprises a roughness of ≦6 μm. 
     
     
         8 . The blade or vane as claimed in  claim 1 , wherein the surface of the pressure side comprises a roughness of ≧20 μm. 
     
     
         9 . The blade or vane as claimed in  claim 1 , wherein the surface of the pressure side comprises a roughness of 20 μm to 30 μm. 
     
     
         10 . The blade or vane as claimed in  claim 1 , wherein roughness of the surface of the suction side is at least 20% less rough than the surface of the pressure side. 
     
     
         11 . The blade or vane as claimed in  claim 1 , wherein the blade or vane is for a compressor or a turbine. 
     
     
         12 . A process for producing a blade or vane, comprising:
 producing the blade or vane according to  claim 1 ,   wherein only the surface of the pressure side of the blade or vane is roughened.   
     
     
         13 . A process for producing a blade or vane, comprising:
 producing the blade or vane according to  claim 1 ,   wherein only the surface of the suction side of the blade or vane is smoothed.