Turbine Blade With Recessed Tip

Abstract

A turbine blade ( 1 ) with a side surface ( 7 ) having an aerodynamic profile. The turbine blade ( 1 ) further comprises an end surface ( 6 ) and is mounted in a turbine, whereby the end surface ( 6 ) is delimited by a gap from a casing ( 8 ) of the turbine. The end surface ( 6 ) comprises a recess ( 2 ) which is shaped such that it acts as an improved aerodynamic seal.

1 . A turbine blade ( 1 ) comprising:
 a side surface ( 7 ) having an aerodynamic profile and an end surface ( 6 ) arranged in a mounted position in a turbine delimited by a gap ( 12 ) from a casing ( 8 ) of the turbine, the end surface ( 6 ) comprising a recess ( 2 ) which is shaped such that it acts as an aerodynamic seal, wherein the recess ( 2 ) is delimited by a side wall ( 4 ) which has a variable wall thickness (t) in a circumferential direction of the turbine blade ( 1 ).   
   
   
       2 . The turbine blade ( 1 ) according to  claim 1 , wherein the side wall ( 4 ) has a generally constant wall thickness (t) in a height direction ( 0 ). 
   
   
       3 . The turbine blade ( 1 ) according to  claim 1  wherein the wall thickness (t) of the side wall ( 4 ) has an overall maximum ( 15 ) on a suction side of the turbine blade ( 1 ) in an area where the turbine blade ( 1 ) has its maximum thickness ( 14 ). 
   
   
       4 . The turbine blade ( 1 ) according to  claim 1  wherein the wall thickness (t) of the side wall ( 4 ) has a maximum ( 15 ) on a suction side of the turbine blade ( 1 ) between +0% and +50% relative length with respect to the blade leading edge ( 0 ). 
   
   
       5 . The turbine blade ( 1 ) according to  claim 4 , wherein the maximum ( 15 ) is arranged between +10% and +40% relative length with respect to the blade leading edge ( 0 ). 
   
   
       6 . The turbine blade ( 1 ) according to  claim 4  wherein the maximum ( 15 ) is an overall maximum. 
   
   
       7 . The turbine blade ( 1 ) according to  claim 4  wherein the wall thickness (t) is on the suction side of the turbine blade ( 1 ) on both side of the maximum ( 15 ) continuously decreasing. 
   
   
       8 . The turbine blade ( 1 ) according to  claim 1  wherein a wall thickness (t) of the side wall ( 4 ) has on the pressure side of the turbine blade ( 1 ) a minima in the range between −0% and −70% relative length with respect to the blade leading edge ( 0 ). 
   
   
       9 . The turbine blade ( 1 ) according to  claim 8  wherein the wall thickness (t) on the suction side of the turbine blade ( 1 ) is at least partially constant. 
   
   
       10 . The turbine blade ( 1 ) according to  claim 8  wherein the wall thickness (t) on the pressure side of the turbine blade ( 1 ) is at least partially constant. 
   
   
       11 . The turbine blade ( 1 ) according to  claim 10 , wherein the wall thickness (t) on the pressure side is constant in the range between −5% and −50% relative length with respect to the blade leading edge ( 0 ). 
   
   
       12 . The turbine blade ( 1 ) according to  claim 1  wherein an overall maximum ( 15 ) of the wall thickness (t) of the side wall ( 4 ) is about 2 to 8 times bigger then an overall minima. 
   
   
       13 . The turbine blade ( 1 ) according to  claim 12 , wherein the overall maximum ( 15 ) of the wall thickness (t) of the side wall ( 4 ) is about 5.5 to 6.5 times bigger then the overall minima. 
   
   
       14 . The turbine blade ( 1 ) according to  claim 1  wherein the recess ( 2 ) has a generally constant depth ( 0 ). 
   
   
       15 . A turbine formed with the turbine blade ( 1 ) of  claim 1 .