Ice shed reduction for leading edge structures

Abstract

A leading edge structure for use in an aerospace vehicle includes a body having a flowpath surface which defines a leading edge adapted to face an air flow during operation, and an opposed inner surface. The body is segmented into a plurality of portions having varying thermal properties and/or mechanical discontinuities, so as to promote stress concentrations in ice attached to the flowpath surface.

1 . A leading edge structure for use in an aerospace vehicle, comprising:
 (a) a body having a flowpath surface which defines a leading edge adapted to face an air flow during operation; and   (b) a plurality of mechanical discontinuities formed in the flowpath surface, the mechanical discontinuities adapted to promote stress concentrations in ice attached to the flowpath surface.   
     
     
         2 . The leading edge structure of  claim 1  wherein the discontinuities are defined by one or more ribs extending from the flowpath surface. 
     
     
         3 . The leading edge structure of  claim 2  wherein the ribs are curved so as to be generally parallel to the expected flowfield around the flowpath surface during operation. 
     
     
         4 . The leading edge structure of  claim 1  wherein the discontinuities are defined by adjacent portions of the flowpath surface which are offset from each other. 
     
     
         5 . The leading edge structure of  claim 4  wherein faces defined by adjacent portions of the flowpath surface are curved so as to be generally parallel to the expected flowfield around the flowpath surface during operation. 
     
     
         6 . The leading edge structure of  claim 1  wherein the body comprises aluminum. 
     
     
         7 . A splitter for a turbofan engine, comprising:
 (a) an annular body having a flowpath surface which defines a leading edge adapted to face an air flow during operation; and   (b) a plurality of mechanical discontinuities formed in the flowpath surface, the mechanical discontinuities adapted to promote stress concentrations in ice attached to the flowpath surface.   
     
     
         8 . The splitter of  claim 7  wherein the discontinuities are defined by one or more ribs extending from the flowpath surface. 
     
     
         9 . The splitter of  claim 8  wherein the ribs are curved so as to be generally parallel to the expected flowfield around the flowpath surface during operation. 
     
     
         10 . The splitter of  claim 8  wherein the flowpath surface has a radial array of generally axially-aligned ribs protruding therefrom. 
     
     
         11 . The splitter of  claim 7  wherein the discontinuities are defined by adjacent portions of the flowpath surface which are offset from each other. 
     
     
         12 . The splitter of  claim 11  wherein faces defined by adjacent portions of the flowpath surface are curved so as to be generally parallel to the expected flowfield around the flowpath surface during operation. 
     
     
         13 . The splitter of  claim 7  wherein the body comprises aluminum. 
     
     
         14 . A leading edge structure for use in an aerospace vehicle, comprising a body having a flowpath surface which defines a leading edge adapted to face an air flow during operation, and an opposed inner surface; wherein the body is segmented into a plurality of portions having varying thermal properties, so as to promote stress concentrations in ice attached to the flowpath surface. 
     
     
         15 . The leading edge structure of  claim 14  wherein adjacent portions of the body have different thicknesses. 
     
     
         16 . The leading edge structure of  claim 15  wherein the flowpath surface is substantially free from discontinuities. 
     
     
         17 . The leading edge structure of  claim 14  wherein adjacent portions of the body are constructed of different alloys. 
     
     
         18 . The leading edge structure of  claim 14  wherein adjacent portions of the body have different surface textures of the flowpath surface.