Methods of manufacturing turbomachines blades with shaped channels by additive manufacturing, turbomachine blades and turbomachines

Abstract

A hollow blade for a turbomachine comprises an airfoil portion; the airfoil portion extends longitudinally for a length; the airfoil portion is defined laterally by an external surface; the airfoil portion has at least one internal cavity extending along said length and defined laterally by an internal surface; the airfoil portion has a set of channels extending from the external surface to the internal surface; the openings of said channels on said external surface are aligned along a curved line that reflects an isobar on said external surface.

What is claimed is: 
     
         1 . A hollow blade for a turbomachine, the hollow blade comprising:
 an airfoil portion, wherein the airfoil portion extends longitudinally for a length, wherein the airfoil portion is defined laterally by an external surface, wherein the airfoil portion has at least one internal cavity extending along the length and defined laterally by an internal surface, wherein the airfoil portion comprises a set of channels extending from the external surface to the internal surface, and wherein the openings of the channels on the external surface are aligned along a curved line that reflects an isobar on the external surface.   
     
     
         2 . The hollow blade of  claim 1 , wherein the airfoil portion comprises two internal cavities extending along the length and defined laterally by internal surfaces, and two corresponding sets of channels extending from the external surface to the internal surfaces, and wherein the openings of the channels on the external surface are aligned along two corresponding curved lines that reflect isobars on the external surface. 
     
     
         3 . The hollow blade of  claim 2 , wherein a first curved line of the two curved lines is on a pressure side of the airfoil portion, and wherein a second curved line of the two curved lines is on a suction side of the airfoil portion. 
     
     
         4 . The hollow blade of  claim 1 , wherein at least some of the channels are straight and inclined or straight and curved, with respect to the external surface. 
     
     
         5 . The hollow blade of  claim 2 , wherein at least some of the channels are straight and inclined or straight and curved, with respect to the external surface. 
     
     
         6 . The hollow blade of  claim 3 , wherein at least some of the channels are straight and inclined or straight and curved, with respect to the external surface. 
     
     
         7 . The hollow blade of  claim 1 , wherein the channels start in a leading edge region of the hollow blade. 
     
     
         8 . The hollow blade of  claim 1 , wherein the channels start in a trailing edge region of the hollow blade. 
     
     
         9 . The hollow blade of  claim 1 , wherein the channels are shaped to facilitate flow of fluid from the external surface to the internal surface. 
     
     
         10 . The hollow blade of  claim 1 , wherein the channels are shaped to facilitate flow of fluid from the internal surface to the external surface. 
     
     
         11 . The hollow blade of  claim 1 , wherein the hollow blade is arranged as a stator blade of a steam turbine. 
     
     
         12 . The hollow blade of  claim 1 , wherein the hollow blade is in a single piece. 
     
     
         13 . A turbomachine, comprising:
 a plurality of hollow blades, wherein each of the plurality of hollow blade comprises an airfoil portion, wherein the airfoil portion extends longitudinally for a length, wherein the airfoil portion is defined laterally by an external surface, wherein the airfoil portion has at least one internal cavity extending along the length and defined laterally by an internal surface, wherein the airfoil portion comprises a set of channels extending from the external surface to the internal surface, and wherein the openings of the channels on the external surface are aligned along a curved line that reflects an isobar on the external surface.   
     
     
         14 . The turbomachine of  claim 13 , wherein the airfoil portion comprises two internal cavities extending along the length and defined laterally by internal surfaces, and two corresponding sets of channels extending from the external surface to the internal surfaces, and wherein the openings of the channels on the external surface are aligned along two corresponding curved lines that reflect isobars on the external surface. 
     
     
         15 . The turbomachine of  claim 14 , wherein a first curved line of the two curved lines is on a pressure side of the airfoil portion, and wherein a second curved line of the two curved lines is on a suction side of the airfoil portion. 
     
     
         16 . The turbomachine of  claim 15 , wherein at least some of the channels are straight and inclined or straight and curved, with respect to the external surface. 
     
     
         17 . A method of manufacturing a hollow blade for a turbomachine, the hollow blade comprising an airfoil portion, wherein the airfoil portion extends longitudinally for a length, wherein the airfoil portion is defined laterally by an external surface, wherein the airfoil portion has at least one internal cavity extending along the length and defined laterally by an internal surface, wherein the airfoil portion comprises a set of channels extending from the external surface to the internal surface, and wherein the openings of the channels on the external surface are aligned along a curved line that reflects an isobar on the external surface, the method comprising:
 obtaining the airfoil portion by additive manufacturing.   
     
     
         18 . The method of  claim 17 , wherein obtaining the airfoil portion by additive manufacturing comprises a single additive manufacturing process for the whole airfoil portion starting from a first end of the airfoil portion and ending at a second end of the airfoil portion.