Turbine blade

Abstract

A turbine blade ( 1 ) includes a plurality of rows of cooling portions ( 4, 4 A, 4 B) that have notch portions ( 41 ) that discharge cooling gas that has been introduced into an internal portion ( 25 ) of a blade portion ( 2 ) onto a ventral side blade surface ( 23 ), and that are formed in rows that are stacked in a direction between the blade front edge and the blade rear edge. This turbine blade ( 1 ) is provided with: turbulence promoting cooling portions ( 4 B) that are provided in the row located furthest to the downstream side from among the plurality of rows, and that have turbulence promoting devices ( 44, 45, 46 ) in areas exposed by the notch portions ( 41 ); and film cooling portions ( 4 A) that are provided in at least one of other rows from among the plurality of rows, and that form a film cooling layer in the areas exposed by the notch portions ( 41 ).

What is claimed is: 
     
         1 . A turbine blade that is provided with a plurality of rows of cooling portions that have notch portions that discharge cooling gas that has been introduced into an internal portion of a blade portion onto a ventral side blade surface, and that are formed in rows that are stacked in a direction between the blade front edge and the blade rear edge, comprising:
 turbulence promoting cooling portions that are provided in the row located closest to the downstream side from among the plurality of rows, and that have turbulence promoting devices in areas exposed by the notch portions; and   film cooling portions that are provided in at least one of other rows from among the plurality of rows, and that form a film cooling layer in the areas exposed by the notch portions.   
     
     
         2 . The turbine blade according to  claim 1 , wherein, in at least one of the plurality of rows, the plurality of cooling portions are placed discretely from each other in the height direction of the blade portion. 
     
     
         3 . The turbine blade according to  claim 1 , wherein, in at least one of the plurality of rows, the cooling portions are provided continuously in an elongated shape in the height direction of the blade portion. 
     
     
         4 . The turbine blade according to  claim 1 , wherein the turbulence promoting device is formed by a plurality of pin portions that stand upright in the areas exposed by the notch portions. 
     
     
         5 . The turbine blade according to  claim 1 , wherein the turbulence promoting device is formed by a plurality of step portions that stand upright in the areas exposed by the notch portions and that are stacked in rows in the flow direction of the cooling gas. 
     
     
         6 . The turbine blade according to  claim 1 , wherein the turbulence promoting device is formed by a plurality of dimple portions that are formed in the areas exposed by the notch portions.