Bucket airfoil for a turbomachine

Abstract

A turbomachine bucket airfoil includes a root end, a tip end spaced from the root end, and an airfoil surface extending between the root end and the tip end. The airfoil surface includes an upstream edge, a downstream edge, a pressure side and a suction side defining a natural blade profile. The airfoil surface includes a blade span zone having a part span shroud zone. A first part span shroud projects outwardly of the pressure side in the part span shroud zone, and a second part span shroud projects outwardly of the suction side in the part span shroud zone. The turbomachine bucket airfoil includes an interruption of the natural blade profile in the part span shroud zone.

What is claimed is: 
     
         1 . A turbomachine bucket airfoil comprising:
 a root end;   a tip end spaced from the root end;   an airfoil surface extending between the root end and the tip end, the airfoil surface including an upstream edge, a downstream edge, a pressure side and a suction side defining a natural bucket profile, the airfoil surface including a blade span zone defining a part span shroud zone;   a first part span shroud projecting outwardly of the pressure side in the part span shroud zone;   a second part span shroud projecting outwardly of the suction side in the part span shroud zone,   wherein the turbomachine bucket airfoil includes an interruption of the natural bucket profile in the part span shroud zone.   
     
     
         2 . The turbomachine bucket airfoil according to  claim 1 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 25% of the blade span zone outwardly of the centerline toward the tip end and up to about 25% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         3 . The turbomachine bucket airfoil according to  claim 2 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 15% of the blade span zone outwardly of the centerline toward the tip end and up to about 15% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         4 . The turbomachine bucket airfoil according to  claim 3 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 10% of the blade span zone outwardly of the centerline toward the tip end and up to about 10% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         5 . The turbomachine bucket airfoil according to  claim 2 , wherein each of the first and second part span shrouds arranged outwardly of the centerline towards the tip end of corresponding ones of the pressure side and the suction side of the airfoil surface. 
     
     
         6 . The turbomachine bucket airfoil according to  claim 1 , wherein the airfoil surface includes a chord length defined between the upstream edge and the downstream edge, wherein the interruption of the natural bucket profile comprises a change in the chord length in the part span shroud zone. 
     
     
         7 . The turbomachine bucket airfoil according to  claim 6 , wherein the change in chord length comprises an increase in chord length in the part span shroud zone. 
     
     
         8 . The turbomachine bucket airfoil according to  claim 1 , further comprising: a change in a natural bucket airfoil profile of at least one of the pressure side and the suction side in the part span shroud zone. 
     
     
         9 . The turbomachine bucket airfoil according to  claim 8 , wherein the change in the natural bucket airfoil profile of the at least one of the pressure side and the suction side in the part span shroud zone comprises a change in the natural bucket airfoil profile of each of the pressure side and the suction side in the part span shroud zone. 
     
     
         10 . The turbomachine bucket airfoil according to  claim 1 , wherein the interruption of the natural bucket profile in the part span shroud zone establishes a Zweifel loading coefficient of between about 0.5 and about 0.8 in the part span shroud zone. 
     
     
         11 . A turbomachine comprising:
 a compressor portion;   a turbine portion operatively connected to the compressor portion;   a combustor assembly fluidically connected to the compressor portion and the turbine portion; and   a turbomachine bucket airfoil arranged in one of the compressor portion and the turbine portion, the turbomachine bucket airfoil comprising:
 a root end; 
 a tip end spaced from the root end defining a blade span zone; 
 an airfoil surface extending between the root end and the tip end, the airfoil surface including an upstream edge, a downstream edge, a pressure side and a suction side defining a natural bucket profile, the airfoil surface including a blade span zone defining a part span shroud zone; 
 a first part span shroud projecting outwardly of the pressure side in the part span shroud zone; 
 a second part span shroud projecting outwardly of the suction side in the part span shroud zone, 
 wherein the turbomachine bucket airfoil includes an interruption of the natural bucket profile in the part span shroud zone. 
   
     
     
         12 . The turbomachine according to  claim 11 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 25% of the blade span zone outwardly of the centerline toward the tip end and up to about 25% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         13 . The turbomachine according to  claim 12 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 15% of the blade span zone outwardly of the centerline toward the tip end and up to about 15% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         14 . The turbomachine according to  claim 11 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 10% of the blade span zone outwardly of the centerline toward the tip end and up to about 10% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         15 . The turbomachine according to  claim 11 , wherein the airfoil surface includes a chord length defined between the upstream edge and the downstream edge, wherein the interruption of the natural bucket profile comprises a change in the chord length in the part span shroud zone. 
     
     
         16 . The turbomachine according to  claim 11 , further comprising: a change in a natural bucket airfoil profile of at least one of the pressure side and the suction side in the part span shroud zone. 
     
     
         17 . A turbomachine system comprising:
 a compressor portion;   an air inlet system fluidically connected to the compressor portion;   a turbine portion operatively connected to the compressor portion;   a combustor assembly fluidically connected to the compressor portion and the turbine portion;   a driven component operatively connected to one of the compressor portion and the turbine portion; and   a turbomachine bucket airfoil arranged in one of the compressor portion and the turbine portion, the turbomachine bucket airfoil comprising:
 a root end; 
 a tip end spaced from the root end; 
 an airfoil surface extending between the root end and the tip end, the airfoil surface including an upstream edge, a downstream edge, a pressure side and a suction side defining a natural bucket profile, the airfoil surface including a blade span zone defining a part span shroud zone; 
 a first part span shroud projecting outwardly of the pressure side in the part span shroud zone; 
 a second part span shroud projecting outwardly of the suction side in the part span shroud zone, 
 wherein the turbomachine bucket airfoil includes an interruption of the natural bucket profile in the part span shroud zone. 
   
     
     
         18 . The turbomachine system according to  claim 17 , wherein the airfoil surface includes a centerline extending between the upstream edge and the downstream edge, the centerline being substantially equidistant from the root end and the tip end, wherein the part span shroud zone is defined between a position up to about 25% of the blade span zone outwardly of the centerline toward the tip end and up to about 25% of the blade span zone radially inwardly of the centerline toward the root end. 
     
     
         19 . The turbomachine system according to  claim 17 , wherein the airfoil surface includes a chord length defined between the upstream edge and the downstream edge, wherein the interruption of the natural bucket profile comprises a change in the chord length in the part span shroud zone. 
     
     
         20 . The turbomachine system according to  claim 17 , further comprising: a change in a natural bucket airfoil profile of at least one of the pressure side and the suction side in the part span shroud zone.