Blade of a fluid-flow machine featuring a multi-profile design

Abstract

A blade of a fluid-flow machine has a cross-section, which in at least one part of the blade height in at least one flow-line profile section is formed by at least two partial profiles separated from each other, with each of the individual partial profiles having the shape of a blade profile.

1 . A blade of a fluid-flow machine, the blade having a cross-section, which in at least one part of a blade height in at least one flow-line profile section is formed by at least two partial profiles separated from each other, with each of the individual partial profiles having a shape of a blade profile. 
   
   
       2 . The blade of  claim 1 , with the at least two partial profiles including a fore-profile and at least one aft-profile of different relative maximum thickness. 
   
   
       3 . The blade of  claim 2 , with one aft-profile having a relative maximum thickness larger by at least 30 percent than the fore-profile. 
   
   
       4 . The blade of  claim 1 , with the at least two partial profiles including a fore-profile and at least one aft-profile of equal relative maximum thickness. 
   
   
       5 . The blade of  claim 1 , with the at least two partial profiles including a fore-profile and at least one aft-profile of equal absolute maximum thickness. 
   
   
       6 . The blade of  claim 1 , with at least one zone of the blade having a multi-profile design being positioned in a center area of the blade height. 
   
   
       7 . The blade of  claim 1 , with at least one zone of the blade having a multi-profile design being positioned on at least one fixed blade end, confined by a blade root/shroud. 
   
   
       8 . The blade of  claim 7 , with at least one zone of the blade having a multi-profile design being positioned on at least one free blade end with a radial gap towards a hub/casing contour. 
   
   
       9 . The blade of  claim 1 , with the multi-profile design being arranged essentially in a meridional flow direction. 
   
   
       10 . The blade of  claim 1 , with the multi-profile design having an inclination in a direction of one blade end. 
   
   
       11 . The blade of  claim 1 , with a gap between two partial profiles defining a contracting flow path, as viewed in a blade height direction. 
   
   
       12 . The blade of  claim 1 , with a trailing edge of a fore profile being arranged in a trailing edge and rim-near zone (TRZ), with the trailing edge-near zone being defined as a portion of the blade between 40 percent and 100 percent of a meridional blade chord length (Cm), and the rim-near zone being defined as blade portions between 0 percent and 40 percent as well as between 60 percent and 100 percent of a blade height/annulus width. 
   
   
       13 . The blade of  claim 2 , with at least one zone of the blade having a multi-profile design being positioned in a center area of the blade height. 
   
   
       14 . The blade of  claim 2 , with at least one zone of the blade having a multi-profile design being positioned on at least one fixed blade end, confined by a blade root/shroud. 
   
   
       15 . The blade of  claim 2 , with at least one zone of the blade having a multi-profile design being positioned on at least one free blade end with a radial gap towards a hub/casing contour. 
   
   
       16 . The blade of  claim 2 , with the multi-profile design being arranged essentially in a meridional flow direction. 
   
   
       17 . The blade of  claim 2 , with the multi-profile design having an inclination in a direction of one blade end. 
   
   
       18 . The blade of  claim 2 , with a gap between two partial profiles defining a contracting flow path, as viewed in a blade height direction. 
   
   
       19 . The blade of  claim 2 , with a trailing edge of a fore profile being arranged in a trailing edge and rim-near zone (TRZ), with the trailing edge-near zone being defined as a portion of the blade between 40 percent and 100 percent of a meridional blade chord length (Cm), and the rim-near zone being defined as blade portions between 0 percent and 40 percent as well as between 60 percent and 100 percent of a blade height/annulus width.