US-12618382-B2 - Thrust reverser comprising at least one deployable deflecting membrane

US12618382B2US 12618382 B2US12618382 B2US 12618382B2US-12618382-B2

Abstract

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 ).

Inventors

Patrick Gonidec
LoÏc Chapelain
Patrick André BOILEAU

Assignees

SAFRAN NACELLES

Dates

Publication Date: 20260505
Application Date: 20230620
Priority Date: 20220622

Claims (14)

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 .

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is the National Stage application of PCT international application PCT/FR2023/050911, filed on Jun. 20, 2023, which claims the priority of French Patent Application No. 2206143, filed Jun. 22, 2022, both of which are incorporated herein by reference in their entireties. TECHNICAL FIELD The invention relates to the field of nacelles and thrust reversers for an aircraft propulsion unit and more particularly to thrust reversers equipped with deployable membranes. PRIOR ART Thrust reversers are devices used to deflect the flow of air passing through the propulsion unit towards the front, so as to shorten landing distances and limit the load on the brakes on the landing gear. The vane reversers currently used in the aeronautical sector comprise cascade vanes integrated into a fixed or mobile structure of the reverser. The mobile structure of the reverser includes one or more movable reverser cowls, and it is mounted so as to be movable in translation in relation to the fixed structure between a forward direct-thrust position, and a retracted reverse-thrust position. In the retracted reverse-thrust position, in order to deflect at least some of the secondary flow towards the vanes, the reverser is usually equipped with sealing flaps which at least partially seal the secondary flow duct when deployed. In a known manner, this forces the air of the secondary flow radially outwards, in the direction of the vanes, which then generate the forward counter-thrust airflow. The flaps are generally pivotably mounted on the radially internal wall of the movable reverser cowls, this wall delimiting the secondary flow duct radially outwards. Thus, recesses are provided in this radially internal wall of the reverser cowls in order to receive the sealing flaps in a retracted position, as adopted in direct jet. However, in direct jet, the presence of the recesses and flaps is a source of aerodynamic disturbances to the secondary flow. Moreover, this presence locally limits the installation of an acoustic panel on the radially internal wall of the reverser cowls. To provide a technical solution to these problems, it has been proposed to replace the flaps by one or more deployable membranes for closing off the secondary flow duct. Such a design is, for example, known in document FR 3 076 864 A1. Though the presence of deployable sealing membranes in the secondary duct makes it possible to limit the total mass of the reverser, the latter is still impacted by the presence of cascade vanes. These vanes in fact incorporate fins/blades intended to divert the flow forwards to obtain the counter-thrust function. The radial height of these diversion fins being limited by the need to house the cascade vanes inside the reverser in direct-jet configuration, it is sometimes necessary to increase the axial length of these vanes in order to have available the sufficient number of fins necessary for obtaining the required counter-thrust performances. This increase in the length of the cascade vanes gives rise to an increase in the length of several components of the reverser, such as the movable cowl or cowls of the reverser, the actuators, etc. This inevitably leads to a greater mass of the reverser as well as to greater drag, synonymous with an increase in the specific fuel consumption. DESCRIPTION OF THE INVENTION To at least partially solve the drawbacks mentioned above, relating to the embodiments of the prior art, the object of the invention is first of all a 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. According to the invention, the thrust reverser also comprises at least one deployable deflecting membrane designed to divert said 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 this deployed configuration said at least one deflecting membrane extends radially outwards beyond the movable reverser cowl in the retracted thrust-reversal position. Thus the invention proves advantageous in that it replaces all or some of the ca