Airfoil with nonlinear cooling passage

Abstract

An example method of manufacturing an airfoil includes providing a ceramic core corresponding to an interior cooling channel. A refractory metal core is provided that corresponds to a cooling passage. The cores are arranged in a mold. An airfoil structure is cast about the cores to provide a turbine engine airfoil. The turbine engine airfoil includes a wall providing the interior cooling channel and an exterior airfoil surface. The cooling passage is provided in the wall and fluidly connects the interior cooling channel to the exterior airfoil surface. The cooling passage includes multiple inlets and multiple outlets respectively adjoining the interior cooling channel and the exterior airfoil surface. At least one of a first inlet and outlet has a different structural flow characteristic than at least one of a second inlet and outlet.

1 . A turbine engine airfoil comprising:
 an airfoil structure having a wall providing an interior cooling channel and an exterior airfoil surface, a cooling passage provided in the wall fluidly connecting the interior cooling channel to the exterior airfoil surface, the cooling passage including at least one inlet and multiple outlets respectively adjoining the interior cooling channel and the exterior airfoil surface, at least one of a first inlet and outlet having a different structural flow characteristic than at least one of a second inlet and outlet.   
     
     
         2 . The turbine engine airfoil according to  claim 1 , wherein the structural flow characteristic includes at least one of length, path and shape. 
     
     
         3 . The turbine engine airfoil according to  claim 2 , wherein the shape includes a cross-sectional area, the first outlet having a different cross-sectional area than the second outlet. 
     
     
         4 . The turbine engine airfoil according to  claim 1 , wherein the cooling passage extends generally axially within the wall, and including a generally axially extending intermediate passage fluidly connecting the inlets to the outlets. 
     
     
         5 . The turbine engine airfoil according to  claim 4 , wherein multiple inlets each include an entrance at the interior cooling channel, and the outlets each include an exit at the exterior airfoil surface, the entrances having a greater cross-sectional area than that of the exits. 
     
     
         6 . The turbine engine airfoil according to  claim 5 , wherein a first entrance includes an area that is greater than a second entrance. 
     
     
         7 . The turbine engine airfoil according to  claim 5 , wherein a first exit has an area that is greater than a second exit. 
     
     
         8 . The turbine engine airfoil according to  claim 1 , wherein the cooling passage includes trip strips. 
     
     
         9 . The turbine engine airfoil according to  claim 1 , wherein the cooling passage is nonlinear. 
     
     
         10 . A method of manufacturing the airfoil of  claim 1 , comprising the steps of:
 providing a ceramic core corresponding to an interior cooling channel;   providing a refractory metal core corresponding to a cooling passage;   arranging the cores in a mold; and   casting an airfoil structure around the cores, wherein the airfoil structure includes a wall separating the interior cooling channel from an exterior airfoil surface, the cooling passage provided in the wall fluidly connects the interior cooling channel to the exterior airfoil surface, the cooling passage including at least one inlet and multiple outlets respectively adjoining the interior cooling channel and the exterior airfoil surface, at least one of a first inlet and outlet having a different structural flow characteristic than at least one of a second inlet and outlet.   
     
     
         11 . The method according to  claim 10 , wherein the refractory metal core providing step includes forming a desired core shape and bending the formed desired core shape to correspond to the cooling passage. 
     
     
         12 . The method according to  claim 11 , wherein the refractory metal core providing step includes providing notches in the cooling passage corresponding to trip strips. 
     
     
         13 . The method according to  claim 11 , wherein the bending step includes the bending the cooling passage into generally an S-shape in a lateral direction. 
     
     
         14 . The method according to  claim 10 , wherein the arranging step includes locating the refractory metal core relative to the ceramic core. 
     
     
         15 . The method according to  claim 10 , wherein the casting step includes forming a diffuser feature in the cooling passage.