Turbine Engine Comprising a Lobed Mixer Having Scoops

Abstract

The invention relates to a lobed mixer ( 8 ) for arranging on the downstream end of a hood ( 4 ) separating the two co-axial streams, respectively inner and outer, the mixer ( 8 ) being shaped so as to have a least one peripheral succession of lobes ( 20, 21 ) which are generally radially oriented in relation to a longitudinal axis (LL′) of the mixer, each lobe ( 20, 21 ) forming a channel extending mainly along the longitudinal axis and comprising at least one peripheral succession of baffles ( 26 ) from the first stream to the second stream and/or from the second stream to the first stream, arranged on said lobes ( 20, 21 ).

1 . A lobed mixer, intended to be placed at the downstream end of a cowl for separating the two coaxial ducts, namely the internal duct and the external duct, the mixer comprising at least one peripheral succession of lobes having a general radial orientation with respect to a longitudinal axis of the mixer, each lobe forming a gutter extending mainly along the longitudinal axis, and comprising at least one peripheral succession of scoops for passage from the first duct to the second duct and/or, inversely, for passage from the second duct to the first duct, which scoops are placed on said lobes, at least one of said scoops being formed by an opening in a wall of the mixer in the region of the lobes, the opening being elongate in a given direction having a mainly axial component, and by a cover located entirely on either the first duct side or the second duct side with respect to said wall, said cover being connected to the edge of the opening apart from over a downstream portion, so as to form a hole for passage between the two ducts, characterised in that the edge of said opening comprises two side portions which gradually diverge from one another going from upstream to downstream. 
     
     
         2 . The lobed mixer according to  claim 1 , wherein the two side portions at the edge of the opening give said opening a convex shape. 
     
     
         3 . The lobed mixer according to  claim 1 , wherein the cover has a flat portion which corresponds to the shape of the opening and which gradually diverges from the wall of the lobe so as to form a slope. 
     
     
         4 . The lobed mixer according to  claim 1 , wherein the lobed mixer comprising a plurality of said scoops between the base lines of the gutters formed by two successive lobes in the circumferential direction. 
     
     
         5 . The lobed mixer according to  claim 1 , wherein the lobed mixer comprising two scoops having different elongation directions between the base lines of the gutters formed by two successive lobes in the circumferential direction. 
     
     
         6 . The lobed mixer according to  claim 1 , wherein the lobed mixer comprising at least one scoop for passage from the first duct to the second duct and one scoop for passage from the second duct to the first duct, between the base lines of the gutters formed by two successive lobes in the circumferential direction. 
     
     
         7 . The lobed mixer according to  claim 1 , wherein said lobes form gutters of which the base lines, having alternately a positive angle of incidence and a negative angle of incidence in the downstream direction with respect to the longitudinal axis are circumferentially successive. 
     
     
         8 . A turbine engine comprising a lobed mixer according to  claim 1 .