Patent ID: 8152456

Claim:
A turbojet compressor comprising: a shroud rotatable about a longitudinal axis of the compressor; and a plurality of blades, each fastened via a root to the shroud and circumferentially spaced apart from one another so as to define between them flow passages for a gas stream passing through the compressor; each blade having a pressure-side surface and a suction-side surface circumferentially opposite from its pressure-side surface, the pressure-side and suction-side surfaces extending axially between a leading edge and a trailing edge of the blade; wherein the shroud presents, level with each blade root: a suction-side ramp adjoining the suction-side surface of the blade and extending axially from the trailing edge of the blade to beyond its leading edge; a pressure-side ramp adjoining the pressure-side surface of the blade and extending axially from the trailing edge of the blade to beyond its leading edge; the pressure-side and suction-side ramps joining together upstream from the leading edge of the blade to form a projection, said projection presenting a profile that is twisted about an axis of the shroud so as to force the gas stream flowing in each flow passage to go around the blade root essentially via the suction-side thereof; the suction-side ramp presenting, between the leading edge and the trailing edge of the blade, a profile that is inclined relative to the outside surface of the shroud so as to deflect the gas stream flowing in the corresponding flow passage from the suction-side surface of the blade towards the pressure-side surface of an adjacent blade; and the suction-side ramp extending circumferentially over a distance that increases progressively from the leading edge to the trailing edge of the corresponding blade.