Thrust reverser comprising at least one deployable deflecting membrane

Abstract

The invention relates to a thrust reverser for an aircraft propulsion assembly, comprising a deployable deflecting or obstructing membrane (132) designed to deflect or obstruct at least a portion of the secondary flow escaping from a radial extraction opening when this membrane is in a deployed configuration adopted when the movable structure of the reverser is in a retreated thrust reversal position. According to the invention, in this deployed configuration, the membrane (132) has a generally radially outwardly curved shape defining, at a base (108) of the membrane, an air inlet opening (110) via which air can enter the membrane, the membrane (132) extending between: - a membrane front portion (102) forming a forward flap reaching to the base of the membrane; and - a membrane rear portion (104) forming a rearward flap reaching to the base of the membrane.

Description

[0001] DESCRIPTION

[0002] TITLE: THRUST REVERSER COMPRISING AT LEAST ONE DEPLOYABLE DEFLECTING MEMBRANE

[0003] Technical field

[0004] The invention relates to the field of nacelles and thrust reversers for aircraft propulsion systems, and, more particularly, to thrust reversers equipped with deployable membranes.

[0005] State of the prior art

[0006] Thrust reversers are devices that deflect the airflow passing through the propulsion system forward, in order to shorten landing distances and limit the load on the brakes on the landing gear.

[0007] The grid reversers currently used in the aeronautical sector comprise deflection grids integrated into a fixed or mobile structure of the reverser. The mobile structure of the reverser comprises one or more mobile reverser cowls, and it is mounted so as to be movable in translation relative to the fixed structure between a forward direct thrust position and a rearward thrust reversal position.

[0008] In the rearward thrust reverser position, to divert at least part of the secondary flow towards the grilles, the reverser is usually equipped with shutters, which, when deployed, at least partially close the secondary flow. In a known manner, this forces the air of the secondary flow radially outwards, towards the grilles, which then generate the counter-thrust airflow forward.

[0009] The flaps are generally pivotally mounted on the radially inner wall of the movable reverser cowls, this wall delimiting the secondary flow radially outwards. Thus, recesses are provided in this radially inner wall of the reverser cowls in order to receive the shutter flaps in the retracted position, as adopted in direct jet. However, in direct jet, the presence of the recesses and the flaps is a source of aerodynamic disturbances on the secondary flow. In addition, this presence locally limits the installation of an acoustic panel on the radially inner wall of the reverser cowls. To provide a technical solution to these problems, it has been proposed to replace the flaps with one or more deployable membranes for closing the secondary flow. Such a design is for example known from document FR 3 076 864 A1.

[0010] While the presence of deployable sealing membranes in the secondary flow path limits the overall mass of the reverser, this mass is still affected by the presence of the deflection grilles. These grilles incorporate fins / vanes designed to straighten the flow forward to achieve the counter-thrust function. Since the radial height of these deflection fins is limited by the need to house the deflection grilles inside the reverser in a direct jet configuration, it is sometimes necessary to increase the axial length of these grilles in order to have the sufficient number of fins necessary to achieve the required counter-thrust performance.

[0011] This increase in the length of the deflection grids generates an increase in the length of several components of the inverter, such as the mobile inverter cover(s), actuators, etc. This inevitably leads to a greater mass of the inverter as well as greater drag, synonymous with an increase in specific consumption.

[0012] To address this issue, it has been proposed to replace all or part of the grilles with one or more deployable deflection membranes, designed to deflect at least part of the secondary flow escaping from the radial extraction opening, when this deflection membrane is in a deployed configuration adopted when the mobile structure is in the rearward thrust reversal position. However, the solutions provided prove to be largely improvable when, for example, an outlet air flow with a non-zero, even significant, tangential component is locally sought, or even an air flow with a zero axial component which does not participate in the counter-thrust.

[0013] Indeed, if the forward axial component of the air flows leaving the deflection membranes is used to obtain the desired counter-thrust, a possible tangential component can be applied in order to limit the projections of air towards the fuselage of the aircraft, and / or in order to avoid the phenomena of reinjection of air within the turbomachine or the adjacent one. Presentation of the invention

[0014] To at least partially resolve the drawbacks mentioned above, relating to the embodiments of the prior art, the invention firstly relates to a thrust reverser for an aircraft propulsion unit, the reverser comprising a fixed structure equipped with a radially internal delimiting wall of a secondary vein of the propulsion unit intended to be crossed by a secondary flow, the reverser also comprising a mobile structure comprising at least one mobile reverser cowl equipped with a radially internal reverser cowl wall delimiting the secondary vein radially outwards, the mobile structure being movable in translation relative to the fixed structure along a longitudinal central axis of the reverser, between an advanced direct thrust position, and a retracted thrust reversal position in which the mobile structure and the fixed structure define axially between them, on the secondary vein,a radial extraction opening for at least a portion of the secondary flow, the thrust reverser also comprising at least one deployable deflection or obstruction membrane designed to deflect or obstruct at least a portion of the secondary flow escaping from the radial extraction opening, when this deflection or obstruction membrane is in a deployed configuration adopted when the mobile structure is in the retracted thrust reversal position. In addition, in this deployed configuration, the membrane has a general shape that is curved radially outwards, and, defining at a base of the membrane, an air inlet opening in the membrane, said deployable deflection or obstruction membrane extending between:,

[0015] - a front portion of membrane forming a flap forward to the base of the membrane; and

[0016] - a rear part of the membrane forming a flap towards the rear to the base of the membrane.

[0017] Thus, the invention proves advantageous in that it replaces all or part of the reverser's deflection grids with one or more deflection or obstruction membranes, capable of deploying to ensure its counter-thrust, tangential flow or obstruction function, when the mobile structure adopts its rearward thrust reversal position. Such a membrane has the advantage of being compact in the non-deployed configuration, adopted when the mobile structure is in the forward direct thrust position, while being capable of extending radially outwards in a substantial manner in its deployed position, to obtain satisfactory counter-thrust performance.

[0018] The domed shape of the membrane allows it to better absorb the pressure forces to which the membrane is subjected. This results in a robust solution particularly suitable for installation in areas of the inverter with high air pressure, while remaining lightweight, inexpensive, and easily repairable / replaceable.

[0019] Furthermore, the domed shape, for example of the dome type, offers multiple possibilities for varying the orientation of the outlet air flow, by making one or more openings of appropriate dimensions and locations through the membrane. In particular, it proves particularly easy to obtain a counter-thrust air flow with a significant tangential component, for example by making one or more air outlet openings on one of the two opposite circumferential faces of the membrane.

[0020] It is even possible to obtain an outlet air flow with zero axial component, or even to locally achieve total obstruction of the air when desired, by not providing any opening through the membrane.

[0021] Finally, it is noted that the invention is the result of technological research aimed at significantly improving aircraft performance and, in this sense, contributes to reducing the environmental impact of aircraft (decarbonization).

[0022] The invention preferably provides at least one of the following optional technical features, taken alone or in combination.

[0023] Preferably, the air inlet opening is delimited by an opening contour comprising:

[0024] - a front portion of opening contour, of rounded shape;

[0025] - a rear portion of opening contour, of rounded shape; and

[0026] - at least one lateral portion of opening contour, and preferably two lateral portions of opening contour, arranged axially between the front and rear portions of opening contour. The particular shape of the air inlet opening contour also contributes to better absorption of the pressure forces to which the membrane is subjected.

[0027] Preferably, said front portion and said rear portion of the membrane each have a general quarter-sphere shape, an intermediate portion of the membrane, in the general shape of a half-cylinder, connecting the front and rear portions of the membrane. This particular shape further improves the absorption of air pressure forces on the membrane. However, other curved shapes may be envisaged, without departing from the scope of the invention.

[0028] Preferably, in its deployed configuration, the membrane extends radially outwardly beyond the movable reverser cowl in the rearward thrust reverser position. Generally, this improves counterthrust performance.

[0029] Preferably, the inverter comprises a membrane support structure in the form of a closed frame on which the base of the membrane is fixed, the frame running along the contour of the air inlet opening in the membrane, and preferably having a circular, elliptical, oval, or oblong shape. This closed frame allows satisfactory absorption of the forces applied to the membrane.

[0030] Preferably, the opening contour is closed and continuous, or discontinuous, but preferably remaining in the same plane.

[0031] Preferably, the two lateral portions of the opening contour are rectilinear / straight, and / or the front and rear portions of the opening contour are each generally semi-circular in shape.

[0032] Preferably, the membrane has at least one air outlet opening, for example made at least in part through one of two opposite circumferential faces of the membrane. As mentioned previously, this particular arrangement of the air outlet opening makes it possible to obtain an air flow with a tangential component, and therefore not purely axial. Other possibilities are conceivable, such as providing one or more air outlet openings on the front / rear flap, or even on an upper surface of the curved membrane.

[0033] Preferably, the membrane has at least one air outlet opening made at least in part through one of the two opposite circumferential faces of the membrane, as well as at least one air outlet opening made at least in part through the other of the two opposite circumferential faces of the membrane. This particular arrangement of the air outlet openings makes it possible to obtain two air flows, each with a tangential component, and in opposite directions. These openings and their resulting flows may be symmetrical or asymmetrical.

[0034] Preferably, the membrane has several air outlet openings, each made at least in part through one of two opposite circumferential faces of the membrane, and succeeding each other axially, the air outlet openings preferably being slits, even more preferably parallel or substantially parallel to each other. This latter arrangement, which may optionally be provided on the two opposite circumferential faces, is similar for example to shark gill slits.

[0035] Preferably, the membrane has an air outlet opening, made at least in part through the other of the two opposite circumferential faces of the membrane, and taking the form of an axially extending slot. This arrangement makes it possible to correctly balance the membrane in pressure when a single outlet flow is actually desired on the first circumferential face. In addition, the flow which leaves the second circumferential face, through the axially oriented slot, hugs the membrane by passing above it radially outwards, thus generating a depression which advantageously contributes to maintaining the shape of the membrane.

[0036] This axially oriented slot solution applies regardless of the configuration of the opening(s) on the opposite circumferential face of the membrane, always with the aim of generating a depression contributing to the shaping of the deployed membrane.

[0037] Preferably, the inverter comprises at least two deployable deflection or obstruction membranes, spaced from each other in the circumferential direction, of the same general shape curved radially outwards and of the same dimension, the two membranes being such that one comprises at least one air outlet opening and the other is devoid of it, or that one comprises at least one air outlet opening according to a first configuration, and the other comprises at least one air outlet opening according to a second configuration distinct from the first.

[0038] In other words, it is possible to start with a membrane of the same shape and size, and then adapt the position / size of the outlet openings to suit the desired outlet flow direction locally within the inverter. This advantageously results in reduced industrial costs.

[0039] Preferably, said at least one deflection or obstruction membrane is mounted on the fixed structure of the inverter.

[0040] The invention also relates to a nacelle for an aircraft propulsion unit, comprising at least one fan cowl, as well as a thrust reverser as described above.

[0041] Finally, the invention also relates to a propulsion assembly for aircraft, comprising a turbomachine and such a nacelle.

[0042] Among the other optional features of the invention, it is noted the presence of at least one other deployable deflection membrane designed to deflect said at least a portion of the secondary flow escaping from the radial extraction opening, when this deflection membrane is in a deployed configuration adopted when the mobile structure is in the retracted thrust reversal position, and in this deployed configuration, said at least one deflection membrane extends radially outwardly beyond the mobile reverser cowl in the retracted thrust reversal position.Here again, such a deflection membrane has the advantage of being compact in the non-deployed configuration, adopted when the mobile structure is in the forward direct thrust position, while being capable of extending radially outwards significantly in its deployed position, to obtain satisfactory counter-thrust performance.

[0043] The proposed solution makes it possible to reduce the axial dimension of the inverter, because the proposed membrane(s) deflect the flow preferably forward, channeling it towards an ejection section preferably substantially perpendicular to the outlet plane of the membranes. Thus, the flow surface is always substantially equal to the outlet section of the membranes, whereas in the case of conventional grids, the ejection is carried out obliquely with respect to the external plane of the grid. In this case of grids, the more the jet is deflected forward, the more the flow surface of the grid is reduced. Also, to obtain a compatible flow rate of the engine, it is then necessary to lengthen the grids axially, with a significant impact on the overall size of the inverter.

[0044] In the case of a membrane, its geometry directs the flow, but it is its outlet section which causes the flow to straighten, while remaining perpendicular to the outlet velocity of this flow.

[0045] With this solution, it is thus possible to further incline the jet to make it as parallel as possible to the axial direction, and therefore to increase its counter-thrust performance, without reducing the flow area. Consequently, the length of the inverter is conditioned by the length of any retained deflection grids, depending on whether these are entirely or partially replaced by these membranes.

[0046] This results in a gain in terms of mass and drag, with the consequence of an improvement in specific consumption. In addition, the general performance of the propulsion system is increased, thanks to the greater freedom in the choice of aerodynamic shapes of the reverser in direct jet, these shapes remaining less or no longer at all conditioned by the need to house the deflection grids in the reverser in direct thrust configuration.

[0047] It is noted that this other deployable deflection membrane(s) are membranes of the inverter capable of generating an output flow with a non-zero forward axial component, and / or a circumferential output flow with a zero axial component. However, for this latter functionality, the generally domed membranes previously described, and objects of the present invention, are preferred.

[0048] Among the other optional features of the invention, it is also noted the presence of at least one other deployable deflection membrane designed to deflect at least a portion of the secondary flow escaping from the radial extraction opening, when this deflection membrane is in a deployed configuration adopted when the mobile structure is in the retracted thrust reversal position, the reverser comprising a membrane support structure. In this deployed configuration, the membrane has a general shape that is curved radially outward, extending between a front membrane end secured to a front frame of the support structure, and a rear membrane end secured to a rear frame of the support structure. In addition, in its deployed configuration, the deflection membrane extends radially outward without going beyond the mobile reverser cowl in the retracted thrust reversal position.

[0049] Thus, this other type of membrane also has the advantage of being compact in the non-deployed configuration, adopted when the mobile structure is in the forward direct thrust position. The simple shape of the membrane makes it economical, and its relatively low radial extension outwards makes it particularly well suited to installation in areas of the inverter with low air pressure. In other words, this membrane remains light, inexpensive, and easily repairable / replaceable.

[0050] Furthermore, the curved shape, for example of the flattened arch type, offers several possibilities for varying the orientation of the outlet air flow. In particular, it proves particularly easy to obtain a counter-thrust air flow with a significant tangential component, or even an outlet air flow with a zero axial component. Other advantages and characteristics of the invention will appear in the detailed non-limiting description below.

[0051] Brief description of the drawings

[0052] The following detailed description refers to the attached drawings in which:

[0053] [Fig. 1] is a schematic half-view in longitudinal section of a propulsion assembly, comprising a thrust reverser shown in a direct thrust configuration; [Fig. 2] is a longitudinal half-section view of the reverser equipping the propulsion assembly shown in Fig. 1, with the reverser being in the form of a preferred embodiment of the invention, and shown in a direct thrust configuration;

[0054] [Fig. 3] is a longitudinal half-sectional view similar to that of the preceding figure, with the reverser shown in an intermediate configuration between the direct thrust configuration and the thrust reversal configuration;

[0055] [Fig. 4] is a longitudinal half-sectional view similar to that of the preceding figure, with the reverser shown in a thrust reverser configuration; [Fig. 5] is a perspective view showing several diverter membranes of the reverser shown in the preceding figure, in a deployed membrane configuration, the membrane being in the form of a first type of membrane;

[0056] [Fig. 5A] is a longitudinal half-sectional view showing the aerodynamic continuity between the deflection edge of the fixed structure of the inverter, and the support frame of the deflection membrane;

[0057] [Fig. 6] is a partial perspective view of the reverser, showing deflection membranes according to the first type, but also according to a second type and according to a third type, these membranes being represented in the deployed thrust reversal configuration;

[0058] [Fig. 7] is a perspective view of one of the deflection membranes according to the second type, in the deployed thrust reversal configuration;

[0059] [Fig. 8] is a radial top view of the membrane support structure shown in the preceding figure;

[0060] [Fig. 9] is a radial top view of the membrane shown in Fig. 7;

[0061] [Fig. 10] is a radial top view similar to the preceding one, with the membrane appearing in the form of an alternative;

[0062] [Fig. 11] is a perspective view similar to that of Fig. 7, with the membrane being in the form of an alternative;

[0063] [Fig. 12] is a side view of the membrane shown in the preceding figure;

[0064] [Fig. 13] is a perspective view similar to that of Fig. 7, with the membrane being in the form of an alternative;

[0065] [Fig. 14] is a perspective view similar to that of Fig. 7, with the membrane being in the form of yet another alternative;

[0066] [Fig. 15] is a perspective view similar to that of Fig. 7, with the membrane being in the form of yet another alternative;

[0067] [Fig. 16] is a perspective view similar to that of Fig. 7, with the membrane being in the form of yet another alternative;

[0068] [Fig. 17] is a perspective view similar to that of Fig. 7, with the membrane in the form of yet another alternative; [Fig. 18] is a perspective view of one of the deflecting membranes according to the third type, in the deployed thrust reversal configuration;

[0069] [Fig. 19] is a perspective view of the membrane shown in the preceding figure, from another angle;

[0070] [Fig. 20] is a radial top view of the membrane support structure shown in the preceding figure;

[0071] [Fig. 21] is a perspective view similar to that of Fig. 18, with the membrane being in the form of an alternative;

[0072] [Fig. 22] is a perspective view of the membrane shown in the preceding figure, from another angle;

[0073] [Fig. 23] is a perspective view similar to that of Fig. 21, with the membrane being in the form of another alternative;

[0074] [Fig. 24] is a perspective view of the membrane shown in the preceding figure, from another angle.

[0075] Detailed description of embodiments

[0076] Figure 1 shows an aircraft propulsion unit 1, having a longitudinal central axis A1.

[0077] Subsequently, the terms "upstream" and "downstream" are defined relative to a general direction SI of gas flow through the propulsion unit 1, along the axis Al when the latter generates direct thrust. These terms "upstream" and "downstream" could respectively be substituted by the terms "front" and "rear", with the same meaning.

[0078] The propulsion unit 1 comprises a turbomachine 2, a nacelle 3 as well as a mast (not shown), intended to connect the propulsion unit 1 to a wing (not shown) of the aircraft.

[0079] The turbomachine 2 is in this example a twin-spool, dual-flow turbojet engine comprising, from front to rear, a fan 5, a low-pressure compressor 6, a high-pressure compressor 7, a combustion chamber 8, a high-pressure turbine 9 and a low-pressure turbine 10. The compressors 6 and 7, the combustion chamber 8 and the turbines 9 and 10 form a gas generator. The turbojet engine 2 is provided with a fan casing 11 connected to the gas generator by structural arms 12. The nacelle 3 comprises a front section forming an air inlet 13, a middle section which comprises two fan cowls 14 surrounding the fan casing 11, and a rear section 15.

[0080] In operation, an air flow 20 enters the propulsion unit 1 through the air inlet 13, passes through the fan 5 and then divides into a primary flow 20A and a secondary flow 20B. The primary flow 20A flows in a primary gas circulation vein 21A passing through the gas generator. The secondary flow 20B flows in a secondary vein 21B surrounding the gas generator. The secondary vein 21B is delimited radially inwardly by a fixed internal fairing which envelops the gas generator. In this example, the fixed internal fairing comprises a first section 17 belonging to the middle section 14, and a second section 18 extending rearwardly from the first section 17, so as to form a part of the rear section 15. This second section 18 is an integral part of a fixed structure of a thrust reverser which will be described below.This same section will subsequently be called wall 18 of radially internal delimitation of secondary vein 21B.

[0081] Radially outwardly, the secondary vein 21B is delimited by the fan casing 11, and, in the configuration of FIG. 1, by one or more movable reverser cowls 33 forming a part of the rear section 15 of the nacelle 3, and which will be described later. More precisely, between the fan casing 11 and the reverser cowls 33, there is provided an outer shroud 40 of an intermediate casing 42, the latter comprising the aforementioned structural arms 12, the radially outer end of which is fixed to this shroud 40. The latter therefore also participates in delimiting the secondary vein 21B radially outwardly, by being located in the downstream axial extension of the fan casing 11.

[0082] The nacelle 3 therefore comprises a thrust reverser 30 (shown only schematically and partially in FIG. 1), centered on the axis A1 and comprising on the one hand a fixed structure 31 secured to the fan casing 11, and on the other hand a structure 29 movable relative to the fixed structure 31. The fixed structure 31 comprises for example a front frame 46 which connects it fixedly to the fan casing 11, preferably via a knife-edge flange assembly located downstream of the outer shroud 11. This front frame 46 contains a profiled aerodynamic part called a deflection edge 46B, which guides the flow in an inverted jet.

[0083] In this preferred embodiment, the fixed structure 31 also includes a plurality of deployable deflecting membranes 32, one of which is shown schematically in a non-deployed configuration in FIG. 1.

[0084] Furthermore, the mobile structure 29 comprises the aforementioned mobile reverser cowls 33, for example two cowls 33 each extending over an angular amplitude of approximately 180°. This configuration with two cowls 33 is particularly well suited in the case of a nacelle design in which the cowls / walls 18 are also mounted articulated, the reverser 30 then having a so-called “D-shaped” architecture, known by the English name “D-Duct”. In this architecture, the cowls 18, 33 are connected so as to open / close simultaneously during maintenance operations on the engine. However, other architectures are possible, such as for example a so-called “C-shaped” architecture, known by the English name “C-Duct”, or a so-called “O-shaped” architecture, known by the English name “O-Duct”.

[0085] Each reverser cowl 33 comprises a radially external wall 50 forming an external nacelle aerodynamic surface, as well as a radially internal wall 52 participating in the delimitation of the secondary vein 21B radially outwards. This wall 52 is located in the downstream continuity of the deflection edge 46B, in the direct thrust configuration. The two walls 50, 52 define a housing 54 open axially at the upstream end of the reverser cowl 33, and in which at least a portion of the deflection membranes 32 are located in the direct thrust configuration.

[0086] Figure 1 shows the reverser 30 in a forward thrust configuration, called “direct jet”, corresponding to a standard flight configuration. In this configuration, the cowls 33 of the mobile structure 29 are in a closed position, called the advanced thrust or “direct jet” position, in which these reverser cowls 33 are supported on the fixed structure 31, in particular on the deflection edge 46B forming an integral part of the latter. Indeed, in the direct thrust configuration, the upstream end 52A of the radially internal wall 52 of each cowl 33 is in axial support against the deflection edge 46B. The mobile structure 29 is thus movable in translation relative to the fixed structure 31 along the axis A1 of the reverser, between the advanced direct thrust position shown in Figure 1, and a rearward thrust reversal position which will be described later.In the forward direct thrust position of the mobile structure 29, the deflection membrane(s) 32 in the folded / non-deployed configuration are arranged in the housing 54 of the inverter cowls 33, being isolated from the secondary vein 21B by the radially internal wall 52 of these sliding cowls 33. This wall 52, forming the external wall of the secondary vein, is also called an internal acoustic panel.

[0087] The direct thrust configuration is also shown in Figure 2, while the rearward thrust reverser position of the movable structure 29 is shown in Figure 4. Figure 3 shows the reverser in an intermediate position between the positions of Figures 2 and 4. All of Figures 1 to 5A show a preferred embodiment of the present invention.

[0088] In Figure 4, it is shown that the deflection edge 46B and the upstream end of the movable cowl 33 axially delimit between them, on the secondary vein 21B, a radial extraction opening 56 of at least a portion 20B' of the secondary flow 20B. This opening 56 of the secondary vein 21B is therefore delimited upstream by the deflection edge 46B, which, in a conventional manner, flares radially outwards going towards the rear, to delimit an air flow 20B' intended to pass through this opening 56 when the movable system is in this rearward thrust reversal position. In other words, the deflection edge 46B, here made rigidly, gradually moves away from the axis A1 going from front to rear, to guide / deflect the air through the opening 56 and towards the deployable deflection membrane 32, in the thrust reversal configuration.Conversely, this opening 56 of the secondary stream 21B is in particular delimited downstream by the upstream end 52A of the radially internal part 52 of the cover 33, but also by the upstream end of the radially external wall 50 of this same cover. As will be described later, FIG. 5A shows in more detail the role of the solid extension of the deflection edge included in the solid structure carrying the membrane 32, and its interaction with the geometry of the latter in order to obtain the most homogeneous flow possible at the outlet of the inverter. In order to force at least a part 20B' of the secondary flow 20B towards the opening 56, the inverter 30 comprises one or more closing membranes 58.Subsequently, a single membrane 58 will be described, the assembly of which has, for example, an angular amplitude identical or similar to that of the assembly of deflection membranes 32 which will be described later, and which is located in the same axial and radial plane of the propulsion assembly. Thus, several circumferentially adjacent membranes 58 can be provided within the secondary vein 21B. Nevertheless, the angular extent of the closure membrane 58 can be greater than that of the deflection membrane 32, without departing from the scope of the invention.

[0089] The membrane 58 may be made of a material known to those skilled in the art for this type of application. For example, it may be a non-impregnated fabric, for example aramid fibers. The membrane 58 may also be made using a composite material whose matrix is ​​particularly flexible, for example aliphatic polyurethane, which allows use under different temperature conditions, in particular lower temperatures in the case of an aliphatic polyurethane membrane than in the case of a silicone membrane. The matrix gives a low flexural recovery capacity and the behavior of the structure obtained is indeed that of a membrane.One of the major properties of this sealing membrane 58 is that it can bend in a perfectly reversible manner (elastic or by fiber sliding) with a very small radius of curvature relative to its surface, and has a very small thickness, for example of the order of 0.1 to 3 mm. For information purposes, it is observed that this membrane 58 behaves like a boat sail or a parachute / a flying wing when it is put under pressure.

[0090] A first end 58a of the sealing membrane 58 is fixed to a rear support frame 60 belonging to the fixed structure 31 and running in the circumferential direction, this frame being located in or near a rear axial end of the opening 56 and serving to support the membranes 32. Similarly, a front support frame 70 is provided, also belonging to the fixed structure 31 and running in the circumferential direction, this front frame 70 being located in or near a front axial end of the opening 56 and serving to support the membranes 32. In addition, a second end 58b of the sealing membrane 58, opposite the first membrane end 58a, is fixed to the wall 18. It is noted that the first end 58a can be fixed to the rear of the rear support frame 60 as shown in the figures, or to the front of this same support.

[0091] To do this, connecting rods 62 can be used, a first end of each of which is mounted on the wall 18, preferably by means of a pivot or ball joint 64. This connection 64 can be made using a fitting fixed to the fixed wall 18 and cooperating with the first end of the connecting rod 62a.

[0092] The connecting rods 62 are circumferentially spaced from each other within the secondary vein 21B, and their number may vary.

[0093] Each connecting rod 62 is designed to move from a radially projecting position in the secondary vein 21B, a position shown in FIG. 2 and adopted when the mobile structure 29 occupies its forward direct thrust position, to a downstream folded position, shown in FIG. 4 and adopted when the mobile structure 29 occupies its rearward thrust reversal position. In the projecting position, each connecting rod 62 can adopt a radial or substantially radial orientation relative to the axis A1, while in the folded position, each connecting rod can adopt an axial or substantially axial orientation.

[0094] Elastic means, called elastic return means (not shown), tend to tilt each connecting rod 62 towards its folded / lying position of FIG. 4, in particular when the connecting rod is in its projecting position corresponding to the flight position of the reverser. Thus, at the start of deployment of the reverser, each connecting rod 62 exerts on the membrane 58 a rearward and downward thrust which pulls it into the vein so that the flow which rushes into the housing 54 at the start of transit does not jam the membrane in this housing 54 of the fan cowl 33.

[0095] The second end of each connecting rod 62, opposite the first end, can be connected directly to the second end 58b of the membrane 58. Nevertheless, other preferred solutions are retained, such as those aiming to integrate cables and / or reinforcing straps within the means for attaching the membrane 58 to its associated elements 18, 60. It is noted that the connecting rods 62 are axially positioned so that the trajectory of their second end is tangent or substantially tangent to the interior surface of the acoustic panel 52 in its front part, or so that the trajectory is downward in the vein.

[0096] As can be seen in Figure 2, when the mobile structure 29 occupies its forward direct thrust position, at least a portion of the closure membrane 58 is arranged radially outward relative to the radially internal wall 52 of the reverser cover 33, in the housing 54. As a result, when the mobile structure 29 adopts its forward direct thrust position, the second end 58b of the closure membrane 58 is pinched between the upstream end 52A of the wall 52, and the deflection edge 46B. In order to avoid possible damage to the membrane 58 due to this pinching, the deflection edge 46B may locally have a notch of a shape adapted to receive the upstream end 52A of the wall 52. Thus, the membrane 58 is also pressed into this notch of the deflection edge 46B, by the support of the upstream end of the wall 52.

[0097] As can be seen in Figures 3 and 4, when the mobile structure 29 moves and occupies its rearward thrust reversal position at the end of this movement, the closing membrane 58 is partly in abutment against the upstream end 52A of the radially internal wall 52 of the reverser cowl, thus corresponding to the acoustic panel. More precisely, during the rearward movement of the mobile structure 29, the membrane 58 slides on this upstream end 52A of the radially internal wall 52.

[0098] In the rearward thrust reversal position of Figure 4, the membrane 58 is therefore in axial support downstream against the upstream end 52A. It should be noted that depending on the extent of the axial travel of the reverser, the membrane 58 may no longer be in contact with the internal acoustic panel 52 in the fully deployed position of the reverser, where the cowl 33 is in its most rearward position. The option with contact corresponds to a minimized travel of the reverser, while the option without contact generally corresponds to a smoother membrane shape in reverse jet, therefore more efficient from an aerodynamic point of view.Thus, the part of the membrane 58 which is located radially outwards relative to its bearing zone on the wall 52 closes off a part of the upstream axial opening of the housing 54, while the other part located radially inwards closes off at least a part of the secondary vein 21B, thereby diverting at least a part 20B' of the secondary flow 20B towards the opening 56 in the direction of the deployable diversion membrane 32. The material used to produce the membrane 32 is any one of those already mentioned above for producing the closing membrane 58.

[0099] As mentioned previously, in this preferred embodiment, several deflection membranes follow one another within the inverter in the circumferential direction, as visible in Figure 6. More precisely, here three types of membranes are implemented in the inverter, the first type corresponding to the deflection membrane 32 detailed in Figures 1 to 5, and essentially intended to generate counter-thrust forces. A second type of membrane, specific to the present invention, makes it possible to generate counter-thrust forces as well as air outlet flows with a non-zero tangential component, and can even be declined so as to generate an obstruction of the flow taken from the secondary flow. These are the membranes referenced 132 in the figures. Finally, a third type of membrane also makes it possible to generate counter-thrust forces but also air outlet flows with a non-zero tangential component.These are the membranes referenced 232 in the figures.

[0100] As regards the membranes 32 of the first type, each of them corresponds to a downstream deflection membrane which is fixed on a membrane support structure 66, here an open frame of general U-shape oriented axially, and open towards the front as shown in figure 5. The base of the membrane 32 is fixed to the structure 66, all along the latter, for example using a simple hem or using other conventional techniques.

[0101] A front interface piece 67 establishes the mechanical junction between the two free ends of the U-shaped frame 66 and the front support frame 70, while a rear interface piece 69 establishes the mechanical junction between the rounded base of the U-shaped frame 66, and the rear support frame 60. It is noted that the axial length of the frame 66 is identical or substantially identical to the axial length of the opening 56.

[0102] More precisely, the deflection membrane 32 comprises a main deflection portion 74, of which a concave active deflection surface 74a has a leading edge 76 fixed on the rounded base of the U-shaped frame 66, this leading edge therefore being located at a rear axial end of the radial extraction opening 56.

[0103] Figure 5A shows that the front interface part 67 has a solid extension function of the deflection edge 46B, since it has a profiled shape located in the aerodynamic continuity of the latter. This bypass zone with a small radius of curvature, formed by the front interface part 67, makes it possible to obtain a homogeneous direction outlet jet substantially perpendicular to the leak outlet section of the main deflection portion 74 of the membrane 32, located at a trailing edge 78 thereof.

[0104] Furthermore, at this trailing edge 78, it is noted that the membrane 32 can be equipped with a fabric reinforcement 83 shown in FIG. 5A, in particular to reinforce the parallelism of its radial flanks 80.

[0105] In operation, the secondary flow 20B passes through the secondary vein 21B, and comes to abut at least in part on the deployed sealing membrane 58, which forces a portion 20B' of this flow to pass through the opening 56, therefore to pass through the opening defined internally by the frame 66. The flow of the portion of flow 20B' through the extraction opening 56 thus has the consequence of pressurizing the concave active deflection surface 74a, and therefore of deploying the deflection membrane 32 to its fully deployed configuration shown in FIGS. 4 and 5 and 5A.

[0106] The main deflection portion 74, and its concave active inner deflection surface 74a, have the same curved shape which makes it possible to gradually straighten the flow portion 20B' initially of radial or substantially radial orientation upon exiting the opening 56, to result in a counter-thrust flow 20B'' oriented forward, for example with a significant component parallel to the axis A1. This direction of the counter-thrust flow 20B'', which can be adapted according to the needs encountered, is substantially parallel to a tangent to the trailing edge 78 of the main deflection portion 74 and its concave active inner deflection surface 74a. The main portion 74 and its inner active surface 74a may for example extend in the form of an arc of a circle or the like, preferably over an angular extent of between 75 and 90°.With this first type of membrane 32, a counter-thrust function is preferably sought, so the air outlet flow 20B'' used for this counter-thrust preferably has a zero tangential component. Only an axial component is present, along which the U-shaped frame 66 is oriented, and possibly a radial component.

[0107] In Figure 2, the membrane 32 is shown in the folded / non-deployed configuration, as adopted when the mobile structure 29 of the reverser is in the forward direct thrust position. The folded membrane 32 is thus located in the housing 54 of the mobile reverser cowl 33, being covered radially by the wall 50 of this cowl, and being preferentially arranged radially outwardly relative to the closure membrane 58 which is also non-deployed.

[0108] The membrane 32 also comprises, circumferentially on either side of its main deflection portion 74, respectively two radial flanks 80 visible in FIG. 5. The inner surface of these two radial flanks 80 jointly delimit, with the concave active inner deflection surface 74a of the main portion 74, a channel 82 for forward deflection of the part 20B' of the secondary flow escaping from the radial extraction opening 56, to then generate the counter-thrust flow 20B''. With the presence of these radial flanks 80 which run along and are respectively fixed to the two lateral branches of the U-shaped frame 66, the membrane 32 takes a general “hood” shape, the channel 82 of which it delimits internally is of a forward-angled shape, passing from a radial or substantially radial orientation to an axial or substantially axial orientation.To do this, each axial flank 80 of the membrane 32 adopts a generally triangular, almost planar shape, with one of its sides arched, following the concave shape of the active deflection surface 74a.

[0109] One of the particularities of this first type of membrane 32 therefore consists in providing a shape making it possible to deflect forward the part of the flow 20B' escaping from the opening 56, when this deflection membrane is in the deployed configuration of FIG. 4. In addition, for increased performance of the reverser and for a smaller dimensioning thereof, in this deployed configuration, the downstream membrane 32 extends radially outwards beyond the movable reverser cowl 33 in the retracted thrust reversal position. The membrane 32 can thus extend beyond the wall 50 of the cowl 33 over a projecting radial distance “Drs”.

[0110] It is noted that the meridian section of the membrane 32 may advantageously be a circle. This membrane then has a height equal to the axial length of the lumen formed by the frame 66 supporting the hood-shaped membrane. It may, however, be advantageous to transform this shape into an elliptical sector, more flattened than a circular sector, in order to reduce the passage section slightly as it approaches the outlet section. This creates a slightly accelerated and more stable flow. Very preferably, the membrane 32 protrudes from the aerodynamic lines of the wall 50 by several centimeters in the radial direction.This projecting radial distance “Drs” can approximately be of the order of 50% to 90% of the radial height of vein 21B in line with the reverser, for example in the plane where the dimension line of the reference “Drt” is located in FIG. 4, this reference corresponding to the total radial distance of the reverser taken radially between the axis Al and the trailing edge 78 of the main deflection portion 74 in the deployed configuration.

[0111] In the preferred embodiment described above, the deflection membrane 32 defines a single deflection channel 82. However, according to an alternative embodiment, the deflection channel 82 can delimit, using intermediate radial flanks parallel to the radial flanks 80 and located between them, several deflection compartments separated circumferentially from each other. In this case, the main deflection portion 74 can remain continuous in shape along the circumferential direction, or else be in the form of successive lobes along the circumferential direction, each new lobe being initiated at the radially external end of each radial flank.

[0112] Figures 7 to 17 show different membranes 132 of the second type, capable of deploying to provide the counter-thrust, tangential flow or obstruction function, when the mobile structure adopts its rearward thrust reversal position. This second type of membrane, specific to the present invention, has a curved shape and an air inlet opening contour which make it possible to satisfactorily absorb significant pressure forces applied to the membrane. This second type of membrane 132 thus proves to be particularly suitable for installation in the zones of the reverser with high air pressure, i.e. the most loaded zones. Unlike the first type of membrane described previously, the second type of membrane is preferentially chosen to locally obtain a lateral deviation of the air outlet flow, with a non-zero, or even significant, tangential component.In this regard, it is noted that this tangential component may be sought in order to limit air projections towards the fuselage of the aircraft, and / or in order to avoid air reinjection phenomena within the turbomachine or the adjacent turbomachine.

[0113] Firstly, with reference to figures 7 to 9, a membrane 132 is shown which, in the deployed configuration, has a general shape that is curved radially outwards, here in the form of a dome extending lengthwise in the axial direction.

[0114] More specifically, the deployable deflection membrane 132 has a front portion 102 forming a flap forward to the base of the membrane, and preferably adopting a general quarter-sphere shape opening radially inward and axially rearward. Similarly, the membrane 132 comprises a rear portion 104 forming a flap backward to the base of the membrane, and also preferably adopting a general quarter-sphere shape opening radially inward and axially forward. The two opposite flaps constitute a strong singularity of the membrane 132, whatever the general shape chosen. The membrane 132 therefore extends between its front membrane portion 102 and its rear membrane portion 104.

[0115] Furthermore, an intermediate part 106 in the general shape of a half-cylinder open axially and radially inwards, connects the front and rear parts 102, 104 of the membrane.

[0116] From a radial amplitude point of view, like the first type of membrane 32, the deployed membrane 132 preferably extends radially outwards beyond the movable reverser cowl in the rearward thrust reverser position. By leaving the aerodynamic lines of the reverser in this way in the thrust reverser configuration, the efficiency of the laterally deflected airflow which leaves this membrane is advantageously reinforced.

[0117] The membrane 132 defines, at a base 108 thereof, an air inlet opening 110 in the membrane. This opening 110 is delimited by an opening contour 112, here closed, and which cooperates with a membrane support structure 166 in the form of a closed frame, here oblong in shape. The base 108 is thus fixed to the frame 166, which runs along the air inlet opening contour 112. Here too, this fixing can be achieved by a hem 114, or any other technique deemed appropriate.

[0118] The opening contour 112, of the same oblong shape as that of the frame 166, is closed and continuous. It comprises several adjacent portions, among which:

[0119] - a front portion of opening contour 112a, of rounded shape, preferably semi-circular, cooperating with a front portion of the same shape of the frame 166;

[0120] - a rear portion of opening contour 112b, of rounded shape, preferably semi-circular, cooperating with a rear portion of the same shape of the frame 166;

[0121] - two lateral portions of opening contour 112c, preferably rectilinear / straight, arranged axially between the front and rear portions of opening contour 112a, 112b, and cooperating respectively with two corresponding rectilinear / straight axial reinforcements of the support 166.

[0122] In this regard, it is noted that the front and rear opening contour portions 112a, 112b may well be offset from each other along the axis A1. However, the membrane may not only extend from front to rear while being parallel or substantially parallel to the axis A1, but also extend while having a circumferential component, and therefore not being parallel to the axis A1. In the latter case, the front and rear opening contour portions 112a, 112b are thus offset from each other along the inclined axis of the membrane, having the aforementioned circumferential component.

[0123] Furthermore, the opening contour 112, and the frame 166, could have a shape other than the oblong shape. For example, the opening contour side portions 112c could be curved so that the opening contour 112 has a generally oval shape, or the opening contour side portions 112c could be rounded in shape so that the opening contour 112 has a generally circular shape.

[0124] The opening contour 112 preferably lies in an axial and tangential plane, and is located in the aforementioned radial extraction opening. Here too, it is noted that the axial length of the frame 166 is identical or substantially identical to the axial length of this radial air extraction opening 56. Moreover, it is also noted that the membrane 132 has the same type of cooperation with a closing membrane 58 in the secondary flow, as that described above for the membrane 32. Similarly, its support structure 166 cooperates with the same type of front and rear interface parts 67, 69, these also being fixed to the front and rear membrane support frames 70, 60.

[0125] In the embodiment shown in Figures 7 to 9, the membrane 132 has several air outlet openings 120, each made at least in part through one of the two opposite circumferential faces 122 of the membrane. These air outlet openings 120 follow one another axially, preferably being in the form of slots that are parallel or substantially parallel to each other. These slots 120 can each extend axially rearward, going radially outward. They are thus similar to shark gill slits, being provided here in a number ranging from two to six slots following one another in the axial direction.

[0126] By arranging the slots 120 on one of the two opposite circumferential faces 122 of the dome-shaped membrane, the resulting air outlet flow 120B'' can easily have a non-zero tangential component 124 to provide the desired lateral deflection function, as well as an axial component 126 that is also non-zero in order to contribute to the counter-thrust, and preferably a zero or substantially zero radial component for better effectiveness of the aforementioned effects.

[0127] The lateral deflection angle of the air outlet flow 120B" relative to the axial direction may, for example, be of the order of 30°, 45° or even 60°. Certain shapes of air outlet openings could even result in a lateral deflection of 90°, bringing the air outlet flow 120B" to a zero axial component. In the mode shown in FIGS. 7 to 9, the openings 120 are arranged mainly on the semi-cylindrical intermediate portion 106, but they could also extend partially over the front and rear portions 102 in the general shape of a quarter sphere.

[0128] As shown in Figure 10, a similar arrangement of openings 120, or even symmetrical with respect to a radial and axial median plane of the membrane 132, could be provided on the opposite circumferential face 122.

[0129] According to an alternative shown in Figures 11 and 12, on this circumferential face opposite that which comprises the axially succeeding openings 122, there is provided an air outlet opening 128 in the form of a slot extending axially, through the semi-cylindrical intermediate part 106, and possibly extending onto one and / or the other of the front and rear parts 102. This arrangement makes it possible to correctly balance the membrane in pressure, with two flows exiting laterally from the two opposite sides of this membrane. In addition, the flow 120B'" which exits through the axially oriented slot 128 hugs the membrane by passing above it radially towards the outside, thus generating a depression which advantageously contributes to maintaining the shape of this membrane. It then joins the outlet air flow 120B" coming from the axial slots 120.

[0130] In the same vein, an opening 130 may be provided on the rear portion of membrane 104, extending substantially circumferentially. The outlet flow 120B'"' also participates in the shaping of the membrane, by depression, before joining the outlet air flow 120B".

[0131] Figure 14 shows an alternative in which a lateral opening 134 of larger area passes through one of the opposite circumferential faces 122 of the membrane. This crossing is carried out up to the opening contour 112, making the latter discontinuous / interrupted at one of the two lateral opening contour portions 112c. The advanced position of the opening 134 on the membrane leads to limiting the angle of deflection of the air outlet flow, but this position can of course be adapted according to the desired angle of deflection. Figure 15 is a similar alternative, in which the air outlet opening 134 does not extend up to the contour 112 of the air inlet opening 110 in the membrane, thus maintaining the contour 112 continuous / uninterrupted.

[0132] Figure 16 shows another variation of the principle of a membrane of the second type in the form of a dome, in which it is simply sought to obstruct the flow which enters the membrane 132, from the opening 110. No outlet opening is made through the membrane, so that no outlet flow is generated locally within the inverter.

[0133] As can be seen in FIG. 6, the inverter may comprise several membranes 132 of this second type, circumferentially spaced from each other and having different outlet opening configurations.

[0134] In this example, it is a membrane 132 according to the configuration of figure 7, followed in the counterclockwise direction by a membrane 132 according to the configuration of figure 14. This results in an industrial advantage, given that these membranes can preferentially be obtained from identical membranes, that is to say having the same shape and the same dimension, preferably those of the closed membrane of figure 16, and which are then pierced with the desired openings.

[0135] Other general curved shapes than that shown on the membranes of Figures 7 to 16 may be provided, such as that of Figure 17 in which the membrane 132 appears to be slightly more flattened in the radial direction. More precisely, it is its three parts 102, 104, 106 which are each more flattened radially.

[0136] Figures 18 to 24 show different membranes 232 of the third type, capable of being deployed to provide the counter-thrust or tangential flow function. This third type of membrane has a curved shape and an air inlet opening contour which make it possible to satisfactorily absorb lower pressure forces than those applied to the membrane of the second type described previously. This third type of membrane 232 is thus particularly suitable for installation in the areas of the inverter with low air pressure, i.e. the least loaded areas. In return, its production is simpler and its cost reduced.

[0137] Unlike the first type of membrane described above, the third type of membrane is preferably chosen to locally obtain a lateral deviation of the air outlet flow, with a non-zero, or even significant, tangential component, possibly even having a zero axial component. In this regard, it is noted that this tangential component may be sought in order to limit air projections towards the fuselage of the aircraft, and / or in order to avoid air reinjection phenomena within the turbomachine or the adjacent turbomachine.

[0138] Firstly, with reference to figures 18 to 20, a membrane 232 is shown which, in the deployed configuration, has a general shape that is curved radially outwards, here in the form of a flattened arch extending lengthwise in the axial direction.

[0139] More specifically, the deployable deflection membrane 232 has a front portion 202 forming a flap forward to the base of the membrane, a rear portion 204 also forming a flap rearward to the base of the membrane, and an intermediate portion 206 which connects the front and rear portions 202, 204 of the membrane. These three portions preferably have the same, relatively small curvature, and they are in continuity with each other. By forward flap, it is understood that the membrane extends downwards going forward, while by rear flap, it is understood that the membrane extends downwards going rearward.

[0140] From a radial amplitude point of view, unlike the first and second types of membrane 32, 132, the deployed membrane 232 extends radially outward without going beyond the movable reverser cowl in the rearward thrust reverser position. This reflects the flattened appearance of the membrane 232, which therefore does not extend beyond the aerodynamic lines of the reverser, radially outward in the thrust reverser configuration.

[0141] The membrane 232 defines, at a base thereof, an air inlet opening 210 in the membrane. This opening 210 is delimited by an opening contour 212, here interrupted, and which cooperates with a membrane support structure 266 in the form of a closed frame, here rectangular in shape. The membrane 232 is thus fixed to the frame 266, which runs along the air inlet opening contour 212. Here too, this fixing can be achieved by a hem 214, or any other technique deemed appropriate. The opening contour 212 comprises several portions, including:

[0142] - a front portion of opening contour 212a, of rectilinear / straight shape parallel to the tangential direction, cooperating with a front portion of the same shape of the frame 266;

[0143] - a rear portion of opening contour 212b, of rectilinear / straight shape parallel to the tangential direction, cooperating with a rear portion of the same shape of the frame 266. The opening contour 212 is thus interrupted at the level of the opposite lateral ends 222 of the membrane 232, since the front end of the membrane 232 is integral with a front frame 224a of the frame 266, and the rear end of the membrane 232 is integral with a rear frame 224b of this frame 266.

[0144] In this regard, it is noted that the front and rear ends of the membrane 232 may well be offset from each other along the axis A1. However, the membrane may not only extend from front to rear while being parallel or substantially parallel to the axis A1, but also extend while having a circumferential component, and therefore not being parallel to the axis A1. In the latter case, the front and rear ends of the membrane are thus offset from each other along the inclined axis of the membrane, having the aforementioned circumferential component.

[0145] On the other hand, at the level of two straight lateral frames 224c of the frame 266, of axial orientation, the opening contour 212 is interrupted over the entire axial length of the membrane, since the opposite lateral ends 222 of the latter are located at a radial distance from these frames 224c.

[0146] The front and rear ends of the membrane 232 are thus preferably rectilinear / straight, while the four frames 224, 224b, 224c are preferably in the form of bars.

[0147] The opening contour 212 preferably lies in an axial and tangential plane, and is located in the aforementioned radial extraction opening. Here too, it is noted that the axial length of the frame 266 is identical or substantially identical to the axial length of this radial air extraction opening 56. Moreover, it is also noted that the membrane 232 has the same type of cooperation with a closing membrane 58 in the secondary flow, as that described above for the membrane 32. Similarly, its support structure 266 cooperates with the same type of front and rear interface parts 67, 69, these also being fixed to the front and rear membrane support frames 70, 60.

[0148] In the embodiment shown in Figures 18 to 20, the membrane 232 has two air outlet openings 220. Each of them is delimited between one of the lateral frames 224c of axial orientation and in the form of a bar, and one of the corresponding lateral ends 222 of the membrane. Each of the two air outlet openings 220, opposite in the circumferential direction, thus generally falls within an axial and radial plane.

[0149] By making the two outlet openings 220 in this way, each of the two resulting air outlet flows 220B'' can easily have a very high tangential component, or even a zero axial component to direct the outlet air tangentially, with possibly a low radial component.

[0150] By deflecting the outlet air at 90° in the tangential direction, it is primarily the lateral deflection function that is targeted, without seeking an axial component likely to contribute to the counter-thrust function.

[0151] Figures 21 and 22 show an alternative, in which only a lateral air outlet opening 220 is provided, between one of the lateral frames 224c and one of the lateral ends 222 of the membrane. This membrane then has a second curvature going from this lateral end 222, to the other lateral end 222 secured to the other lateral frame 224c of the frame 266. This securing can be carried out as for the securing of the front and rear ends of the membrane on their respective frames 224, 224b, continuously along the entire length thereof.

[0152] Whatever the mode envisaged for the membrane 232 of the third type, figures 23 and 24 show the possibility of adding, at the level of the lateral air outlet opening 220, a rear lateral membrane rim 227.

[0153] This lateral edge 227, curved circumferentially and towards the rear, is integral with each of the following elements:

[0154] - one of the two opposite lateral ends 222 of the membrane;

[0155] - the rear end of the membrane corresponding to the terminal portion of its rear part 204; - the rear end of the corresponding lateral frame 224c.

[0156] The addition of this lateral rim makes it possible to limit the axial extent of the air outlet opening 220 towards the rear, with the aim either of seeking a non-zero axial component for the outlet air flow 220B", or, when a tangential flow with a zero axial component is sought, of preventing this flow from being deflected towards the rear when it leaves the opening 220.

[0157] The lateral deflection angle of the air outlet flow 220B'', relative to the axial direction, may for example be of the order of 30°, 45° or even 60°, depending on the axial extent of the rim 1.

[0158] It is noted that such a membrane 232 with one or two lateral edges is easy to obtain, for example by simply cutting a textile, respectively in an L or T shape.

[0159] Finally, it is indicated that whatever the type of membrane considered among those exposed previously, these membranes can be mechanically reinforced by straps or cables.

[0160] Various modifications may be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples, and the scope of which is defined by the appended claims. For example, the thrust reverser 30 may alternatively have a “C” or “O” architecture. Furthermore, the membranes specific to the invention may coexist with conventional grids within the reverser. Furthermore, all the features disclosed above, in the various preferred embodiments and their alternatives, are combinable with each other. Moreover, it is noted that in all the figures which have been described above, the elements which bear the same numerical references correspond to identical or similar elements.Finally, it is noted that the closure of the secondary vein is preferably carried out by a flexible structure, of the membrane / textile type, and / or by a rigid structure, of the classic shutter(s) type of the prior art.

Claims

CLAIMS 1. Thrust reverser (30) for an aircraft propulsion unit, the reverser comprising a fixed structure (31) equipped with a radially internal delimiting wall (18) of a secondary vein (21B) of the propulsion unit intended to be traversed by a secondary flow (20B), the reverser also comprising a movable structure (29) comprising at least one movable reverser cowl (33) equipped with a radially internal reverser cowl wall (52) delimiting the secondary vein (21B) radially outwards, the movable structure being movable in translation relative to the fixed structure along a longitudinal central axis (A1) of the reverser, between an advanced direct thrust position, and a retracted thrust reversal position in which the movable structure (29) and the fixed structure (31) define axially between them, on the secondary vein, a radial extraction opening (56) of at least a portion (20B') of the flow secondary,the thrust reverser also comprising at least one deployable deflection or obstruction membrane (132, 232) designed to deflect or obstruct at least a portion (20B') of the secondary flow escaping from the radial extraction opening (56), when this deflection or obstruction membrane is in a deployed configuration adopted when the mobile structure (29) is in the retracted thrust reversal position, characterized in that in this deployed configuration, the membrane (132, 232) has a general shape curved radially outwards, and, defining at a base (108) of the membrane, an opening (110, 210) for air inlet into the membrane, said deployable deflection or obstruction membrane (132) extending between:, - a front membrane portion (102, 202) forming a flap forward to the base of the membrane; and - a rear membrane portion (104, 204) forming a flap towards the rear up to the base of the membrane.

2. Thrust reverser according to claim 1, characterized in that the air inlet opening (110) is delimited by an opening contour (112) comprising: - a front portion of opening contour (112a), of rounded shape; - a rear portion of opening contour (112b), of rounded shape; and - at least one lateral portion of opening contour (112c), arranged axially between the front and rear portions of opening contour.

3. Thrust reverser according to claim 2, characterized in that said front part (102) of the membrane (132) and said rear part (104) each have the general shape of a quarter sphere, an intermediate part (106) of the membrane (102), in the general shape of a half-cylinder, connecting the front and rear parts of the membrane.

4. Thrust reverser according to any one of the preceding claims, characterized in that in its deployed configuration, the membrane (132) extends radially outwards beyond the movable reverser cowl (33) in the retracted thrust reverser position.

5. Thrust reverser according to any one of the preceding claims, characterized in that it comprises a membrane support structure (166) in the form of a closed frame on which the base (108) of the membrane is fixed, the frame (166) running along the air inlet opening contour (112), and preferably having a circular, elliptical, oval, or oblong shape.

6. Thrust reverser according to any one of the preceding claims, characterized in that the membrane (132) has at least one air outlet opening (120, 128, 130, 134).

7. Thrust reverser according to claim 6, characterized in that the membrane (132) has at least one air outlet opening (120, 128, 130, 134) made at least in part through one of the two opposite circumferential faces (122) of the membrane, as well as at least one air outlet opening (120, 128, 130, 134) made at least in part through the other of the two opposite circumferential faces (122) of the membrane.

8. Thrust reverser according to claim 6 or 7, characterized in that the membrane (132) has several air outlet openings (120), each made at least in part through one of two opposite circumferential faces (122) of the membrane, and succeeding each other axially, the air outlet openings (120) preferably being slots, even more preferably parallel or substantially parallel to each other.

9. Thrust reverser according to any one of the preceding claims, characterized in that it comprises at least two deployable deflection or obstruction membranes (132), spaced from each other in the circumferential direction, of the same general shape curved radially outwards and of the same dimension, the two membranes being such that one comprises at least one air outlet opening and the other is devoid of it, or that one comprises at least one air outlet opening in a first configuration, and the other comprises at least one air outlet opening in a second configuration distinct from the first.

10. Nacelle (3) for an aircraft propulsion unit, comprising at least one fan cowl (14), as well as a thrust reverser (30) according to any one of the preceding claims.

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