Last stage blade including a plurality of leading edge indentations

Abstract

Aspects of the invention provide for a last stage blade of a steam turbine. In one embodiment, the last stage blade of a steam turbine includes: a blade leading edge for receiving a through flow, the blade leading edge including a plurality of indentations at a top portion of the steam turbine blade; and a blade trailing edge for exhausting the through flow.

What is claimed is: 
     
         1 . A steam turbine blade, comprising:
 a blade leading edge for receiving a through flow, the blade leading edge including a plurality of indentations at a top portion of the steam turbine blade; and   a blade trailing edge for exhausting the through flow.   
     
     
         2 . The steam turbine blade of  claim 1 , wherein the top portion of the steam turbine blade includes at least ten percent of the blade. 
     
     
         3 . The steam turbine blade of  claim 1 , wherein the top portion of the steam turbine blade includes no more than twenty percent of the blade. 
     
     
         4 . The steam turbine blade of  claim 1 , wherein, during normal operation, the through flow flows across an entire length of the steam turbine blade. 
     
     
         5 . The steam turbine blade of  claim 1 , wherein, during a low through flow, the through flow flows only across the top portion of the steam turbine blade. 
     
     
         6 . The steam turbine blade of  claim 1 , wherein the steam turbine blade is a last stage blade. 
     
     
         7 . A rotor assembly, comprising:
 a rotor body comprising a plurality of slots;   a plurality of steam turbine blades within the plurality of slots of the rotor body, wherein at least one of the steam turbine blades includes:
 a blade leading edge for receiving a through flow, the blade leading edge including a plurality of indentations at a top portion of the steam turbine blade; and 
 a blade trailing edge for exhausting the through flow. 
   
     
     
         8 . The rotor assembly of  claim 7 , wherein the top portion of the at least one steam turbine blade includes at least ten percent of the blade. 
     
     
         9 . The rotor assembly of  claim 7 , wherein the top portion of the at least one steam turbine blade includes no more than twenty percent of the blade. 
     
     
         10 . The rotor assembly of  claim 7 , wherein, during normal operation, the through flow flows across an entire length of the at least one steam turbine blade. 
     
     
         11 . The rotor assembly of  claim 7 , wherein, during a low through flow, the through flow flows only across the top portion of the at least one of the steam turbine blades. 
     
     
         12 . The rotor assembly of  claim 7 , wherein the at least one steam turbine blade is a last stage blade. 
     
     
         13 . The rotor assembly of  claim 7 , wherein the plurality of steam turbine blades form a plurality of rotor wheels along an axial length of the rotor body. 
     
     
         14 . The rotor assembly of  claim 13 , wherein each of the steam turbine blades of a last stage rotor wheel include the plurality of indentations at the top portion of the blade leading edge. 
     
     
         15 . A steam turbine, comprising:
 a stator; and   a plurality of rotor wheels around the stator, each rotor wheel including:
 a plurality of steam turbine blades, wherein the steam turbine blades of at least one rotor wheel includes:
 a blade leading edge for receiving a through flow, the blade leading edge including a plurality of indentations at a top portion of the steam turbine blade; and 
 a blade trailing edge for exhausting the through flow. 
 
   
     
     
         16 . The steam turbine of  claim 15 , wherein the top portion of the steam turbine blades of the at least one rotor wheel includes at least ten percent of each blade. 
     
     
         17 . The steam turbine of  claim 15 , wherein the top portion of the steam turbine blades of the at least one rotor wheel includes no more than twenty percent of each blade. 
     
     
         18 . The steam turbine of  claim 15 , wherein, during normal operation, the through flow flows across an entire length of the steam turbine blades of the at least one rotor wheel. 
     
     
         19 . The steam turbine of  claim 15 , wherein, during a low through flow, the through flow flows only across the top portion of the plurality of steam turbine blades of the at least one rotor wheel. 
     
     
         20 . The steam turbine of  claim 15 , wherein the steam turbine blades of the at least one rotor wheel are last stage blades.