Annulus filler for axial flow machine

Abstract

A fluid-washed assembly for an axial flow machine, such as a fan blade assembly for a gas turbine engine. The assembly has an array of members circumferentially spaced about the machine axis, each member extending from a radially inner end to a radially outer end with respect to the axis of rotation of the machine. Each member has opposing outer surfaces extending between a leading edge and a trailing edge thereof with respect to the direction of oncoming fluid flow in use. A plurality of annulus fillers are provided between each member, wherein each annulus filler is affixed against an outer surface of an associated member at a location between the inner and outer ends in a manner which supports the annulus filler in use. In preferred embodiments, the annulus fillers comprise a composite material which is bonded to the associated member using an adhesive.

1 . A fluid-washed assembly for an axial flow machine, the assembly comprising:
 an array of members circumferentially spaced about the machine axis, each member extending from a radially inner end to a radially outer end with respect to said axis and having opposing outer surfaces extending between a leading edge and a trailing edge thereof with respect to the direction of oncoming fluid flow in use, and,   a plurality of annulus fillers, wherein each annulus filler is affixed against an outer surface of an associated member at a location between the inner and outer ends in a manner which supports the annulus filler in use.   
     
     
         2 . An assembly according to  claim 1 , wherein the members are supported at their radially inner ends about a common mount and each annulus filler is suspended by the associated member at a radially spaced location from the mount. 
     
     
         3 . An assembly according to  claim 1 , wherein each annulus filler comprises a first wall which extends outwardly from the surface of the associated member, the first wall having an outer surface which defines at least a portion of a fluid-washed surface extending between adjacent members,
 wherein each annulus filler comprises a second wall by which the annulus filler is affixed to the outer surface of the member, the second wall being shaped to lie against said outer surface.   
     
     
         4 . An assembly according to  claim 3 , wherein the second wall defines a contact area, over which the second wall is held against the outer surface. 
     
     
         5 . An assembly according to  claim 3 , wherein the second wall shares a common edge with the first wall and extends in a direction towards the radially inner end of the member. 
     
     
         6 . An assembly according to  claim 3 , wherein the second wall is spaced from the first wall and the first wall is held at a radially outer location relative to the second wall by an intermediate support. 
     
     
         7 . An assembly according to  claim 3 , comprising a third wall extending between the first and second walls and arranged at an angle thereto in order to support the first wall at a location spaced from the outer surface of the member. 
     
     
         8 . An assembly according to  claim 1 , wherein each annulus filler comprises a composite material having reinforcing fibres or particles suspended therein. 
     
     
         9 . An assembly according to  claim 8 , wherein an outer surface of each annulus filler which lies against the outer surface of the associated member comprises a layer of glass fibres. 
     
     
         10 . An assembly according to  claim 1 , wherein each annulus filler extends part way between adjacent members and has an edge which lies adjacent an opposing edge of an adjacent annulus filler so as to form a substantially continuous annulus filler assembly between the adjacent members. 
     
     
         11 . An assembly according to  claim 1 , wherein the inner end of each member comprises an attachment formation and each annulus filler is affixed to the member adjacent, or immediately adjacent, the attachment formation. 
     
     
         12 . An assembly according to  claim 1  wherein each member has an annulus filler joined to both of the opposing surfaces thereof. 
     
     
         13 . An assembly according to  claim 1  wherein the members comprises fan blades of a fan blade assembly and the axial flow machine comprises a gas turbine engine. 
     
     
         14 . An aerofoil for a assembly within a gas turbine engine, the aerofoil having:
 opposing pressure and suction surfaces extending between first and second ends of the aerofoil, said surfaces further extending in a fore and aft direction between a leading edge and a trailing edge of the aerofoil; and,   an annulus filler affixed to at least one of said pressure and suction surfaces so as to define a wall extending outwardly from said surface between the first and second ends thereof,   wherein the annulus filler is affixed to said surface over an area located between the wall and the first end of the aerofoil such that the aerofoil supports the annulus filler in use.   
     
     
         15 . An annulus filler for a gas turbine engine, the annulus filler comprising:
 a first wall portion arranged to define a fluid washed surface in use,   a second wall portion shaped to follow the contour of a pressure or suction surface of a fan blade to which the annulus filler is to be attached, the second wall providing a fixation area for joining the annulus filler to the fan blade surface at a location between the first wall and a root portion of the blade.