Blade with 3d platform comprising an inter-blade bulb

Abstract

A blade for a turbomachine impeller including an airfoil, and a platform extending at one of the ends of the airfoil in a direction globally perpendicular to a longitudinal direction of the airfoil, the blade configured, together with other identical blades, to form a ring around a ring axis, with the adjacent blade platforms joining in pairs so as to form an inter-airfoil surface linking the pressure surface of one airfoil to the suction surface of the neighboring airfoil. In this blade, the inter-airfoil surface includes, in an upstream half of the airfoil, a boss located closer to the pressure surface than to the suction surface, and a recessed passage located between the same and the suction surface.

1 - 12 . (canceled) 
     
     
         13 . A blade for a turbomachine impeller, comprising:
 an airfoil including a pressure surface, a suction surface, a trailing edge, and a leading edge; and   a platform extending at one of the ends of the airfoil in a direction which is globally perpendicular to a longitudinal direction of the airfoil; wherein   the blade is adapted to be arranged with a plurality of substantially identical blades to form a ring around a ring axis and define therealong an upstream and a downstream area, with the ring having the airfoils arranged substantially radially therein, and the adjacent blade platforms joining in pairs so as to form an inter-airfoil surface linking the pressure surface of an airfoil to the suction surface of the neighboring airfoil; and   the inter-airfoil surface comprises in an upstream half of the airfoil, a boss located closer to the pressure surface than to the suction surface, and a recessed passage located between the same and the pressure surface.   
     
     
         14 . The blade according to  claim 13 , wherein the inter-airfoil surface has a profile located in a plane perpendicular to the axis of the ring and located axially in an upstream half of the airfoil, the profile successively comprising the recess followed by the boss, starting from the pressure surface of the airfoil. 
     
     
         15 . The blade according to  claim 13 , wherein the recessed passage comprises a part having a shape of revolution with respect to the ring axis. 
     
     
         16 . The blade according to  claim 13 , wherein the inter-airfoil surface comprises a part of revolution having a shape of revolution with respect to the axis of the ring, located on the side of the suction surface of the airfoil neighboring the boss. 
     
     
         17 . The blade according to  claim 16 , wherein the boss is linked to the part of revolution by a radially descending surface. 
     
     
         18 . The blade according to  claim 13 , wherein the boss includes an apex located axially between 0 and 50% of the airfoil on the upstream side. 
     
     
         19 . The blade according to  claim 18 , wherein the boss includes an apex located axially between 0 and 25% of the airfoil on the upstream side. 
     
     
         20 . The blade according to  claim 13 , wherein the inter-airfoil surface comprises a part having a shape of revolution with respect to the ring axis and extending axially throughout the downstream half of the airfoil. 
     
     
         21 . The blade according to  claim 13 , wherein the boss is continued upstream or downstream of the inter-airfoil surface. 
     
     
         22 . A turbomachine distributor sector, comprising at least one blade according to any of  claim 13 . 
     
     
         23 . An impeller comprising a plurality of blades according to  claim 13 . 
     
     
         24 . A turbomachine comprising at least one impeller according to  claim 23 .