Thrust reverser comprising at least one deployable deflecting membrane
A thrust reverser ( 30 ) for an aircraft propulsion unit, the reverser comprising a stationary structure ( 31 ) and a movable structure ( 29 ) comprising at least one movable reverser cover ( 33 ) delimiting the secondary flow path ( 21 B), the movable structure being translatable with respect to the stationary structure between an advanced direct-thrust position and a retracted thrust-reversal position in which the movable structure ( 29 ) and the stationary structure ( 31 ) axially define therebetween, on the secondary flow path, a radial extraction opening ( 56 ) for at least one portion ( 20 B′) of the secondary flow. The thrust reverser also comprises at least one deployable deflecting membrane ( 32, 32′ ) which is designed to deflect the at least one portion ( 20 B′) of the secondary flow forwards. Moreover, in the deployed configuration, the membrane ( 32, 32′ ) extends radially outwards beyond the movable reverser cover ( 33 ).
1 . Thrust reverser for an aircraft propulsion unit, the reverser comprising a fixed structure equipped with a wall for the radially internal delimitation of a secondary flow duct of the propulsion unit intended to have a secondary flow pass through it, the reverser also comprising a movable structure comprising at least one movable reverser cowl equipped with a radially internal reverser cowl wall delimiting the secondary flow duct radially outwards, the movable structure being movable in translation with respect to the fixed structure on a longitudinal central axis of the reverser, between an advanced direct-thrust position and a retracted thrust-reversal position in which the movable structure and the fixed structure define axially between them, on the secondary flow duct, an opening for radial extraction of at least part of the secondary flow,
wherein the thrust reverser also comprises at least one deployable deflecting membrane designed to deflect at least part of the secondary flow escaping from the radial extraction opening, when this deflecting membrane is in a deployed configuration adopted when the movable structure is in the retracted thrust-reversal position, and in that, in this deployed configuration said at least one deflecting membrane extends radially outwards beyond the movable reverser cowl in the retracted thrust-reversal position.
2 . Thrust reverser according to claim 1 , wherein said at least one deflecting membrane includes a downstream deflecting membrane a concave deflecting active surface of which has a leading edge preferably located at a rear axial end of the radial extraction opening, said concave active deflecting surface being pressurised by said at least part of the secondary flow escaping from the radial extraction opening.
3 . Thrust reverser according to claim 1 , wherein said at least one deflecting membrane includes an upstream deflecting membrane a convex deflecting active surface 84 a ) of which has a leading edge preferentially located at a front axial end of the radial extraction opening, said convex active deflecting surface being put under negative pressure by said at least part of the secondary flow escaping from the radial extraction opening.
4 . Thrust reverser according to claim 2 , wherein said downstream deflecting membrane includes, circumferentially on either side of its active concave deflecting surface, respectively two radial flanks conjointly delimiting, with the active concave deflecting surface, a channel deflecting forwards said at least part of the secondary flow escaping from the radial extraction opening.
5 . Thrust reverser according to claim 4 , wherein said deflecting channel delimits, by way of intermediate radial flanks, a plurality of deflection compartments circumferentially separated from each other.
6 . Thrust reverser according to claim 4 , wherein said downstream deflection membrane is secured to a support frame, preferably with an overall square or rectangular shape, arranged in the radial extraction opening.
7 . Thrust reverser according to claim 1 , wherein a plurality of deflection membranes follow each other circumferentially in the radial extraction opening, optionally in combination with cascade vanes also located in the radial extraction opening, between the deflection membranes.
8 . Thrust reverser according to claim 3 , wherein the upstream deflection membrane, in its deployed configuration, extends a rigid deflection edge of the fixed structure, or forms this same deflection edge.
9 . Thrust reverser according to claim 1 , further comprising at least one deployable sealing membrane which, in a configuration deployed in the secondary flow duct, is designed to deflect at least part of the secondary flow towards the radial extraction opening when the movable structure is in the retracted thrust-reversal position.
10 . Thrust reverser according to claim 2 , wherein, in the deployed configurations of the downstream deflection membrane and of the sealing membrane, a trailing edge of the sealing membrane is offset axially downstream with respect to the leading edge of the active concave diversion surface of the downstream membrane.
11 . Thrust reverser according to claim 2 , further comprising one or more downstream deflection membranes as well as one or more upstream deflection membranes, delimiting together one or more necks for extracting a counter-thrust flow.
12 . Thrust reverser according to claim 1 , wherein said at least one deflection membrane is mounted on the fixed structure of the reverser.
13 . Nacelle for an aircraft propulsion unit, comprising at least one fan cowl, as well as the thrust reverser according to claim 1 .
14 . Propulsion unit for an aircraft, comprising a turbine engine and the nacelle according to claim 13 .