Bucket assembly for turbomachine

Abstract

Bucket assemblies are provided. The bucket assembly includes a shank, and an airfoil positioned radially outward of the shank. The bucket assembly further includes a main cooling circuit defined in the airfoil and the shank, the main cooling circuit comprising seven passages, each of the seven passages fluidly connected with an adjacent one of the seven passages. A maximum rotation number in each of the seven passages is less than or equal to approximately 0.4.

What is claimed is: 
     
         1 . A bucket assembly, comprising:
 a shank;   an airfoil positioned radially outward of the shank;   a main cooling circuit defined in the airfoil and the shank, the main cooling circuit comprising seven passages, each of the seven passages fluidly connected with an adjacent one of the seven passages,   wherein a maximum rotation number in each of the seven passages is less than or equal to approximately 0.4.   
     
     
         2 . The bucket assembly of  claim 1 , wherein the rotation number in each of the seven passages is in a range between approximately 0.01 and approximately 0.35. 
     
     
         3 . The bucket assembly of  claim 1 , wherein a first passage of the seven passages has a maximum cross-sectional area in the airfoil that is in a range between approximately 10% and approximately 20% less than a maximum cross-sectional area in the airfoil of another passage of the seven passages. 
     
     
         4 . The bucket assembly of  claim 1 , further comprising an exhaust passage defined in the airfoil and in fluid communication with a seventh passage of the seven passages. 
     
     
         5 . The bucket assembly of  claim 1 , further comprising a forward cooling circuit and an aft cooling circuit are each defined in the airfoil and the shank. 
     
     
         6 . The bucket assembly of  claim 1 , wherein the main cooling circuit consists of seven passages. 
     
     
         7 . The bucket assembly of  claim 1 , further comprising a platform positioned radially between the shank and the airfoil. 
     
     
         8 . The bucket assembly of  claim 1 , wherein the airfoil has exterior surfaces defining a pressure side and a suction side extending between a leading edge and a trailing edge. 
     
     
         9 . The bucket assembly of  claim 1 , further comprising a dovetail. 
     
     
         10 . The bucket assembly of  claim 1 , wherein the dovetail defines a root, and wherein the main cooling circuit extends to the root. 
     
     
         11 . A turbomachine, comprising:
 an inlet section;   an exhaust section;   a compressor section;   a combustor section; and   a turbine section, the turbine section comprising a plurality of bucket assemblies, each of the plurality of bucket assemblies comprising:
 a shank; 
 an airfoil positioned radially outward of the shank; 
 a main cooling circuit defined in the airfoil and the shank, the main cooling circuit comprising seven passages, each of the seven passages fluidly connected with an adjacent one of the seven passages, 
 wherein a maximum rotation number in each of the seven passages is less than or equal to approximately 0.4. 
   
     
     
         12 . The turbomachine of  claim 11 , wherein the rotation number in each of the seven passages is in a range between approximately 0.01 and approximately 0.35. 
     
     
         13 . The turbomachine of  claim 11 , wherein a first passage of the seven passages has a maximum cross-sectional area in the airfoil that is in a range between approximately 10% and approximately 20% less than a maximum cross-sectional area in the airfoil of another passage of the seven passages. 
     
     
         14 . The turbomachine of  claim 11 , further comprising an exhaust passage defined in the airfoil and in fluid communication with a seventh passage of the seven passages. 
     
     
         15 . The turbomachine of  claim 11 , further comprising a forward cooling circuit and an aft cooling circuit are each defined in the airfoil and the shank. 
     
     
         16 . The turbomachine of  claim 11 , wherein the main cooling circuit consists of seven passages. 
     
     
         17 . The turbomachine of  claim 11 , further comprising a platform positioned radially between the shank and the airfoil. 
     
     
         18 . The turbomachine of  claim 11 , wherein the airfoil has exterior surfaces defining a pressure side and a suction side extending between a leading edge and a trailing edge. 
     
     
         19 . The turbomachine of  claim 11 , further comprising a dovetail. 
     
     
         20 . The turbomachine of  claim 11 , wherein the dovetail defines a root, and wherein the main cooling circuit extends to the root.