FR2891255A1 - Engine e.g. jet engine, assembly for aircraft, has outlet placed in rear with respect to rear engine mount, and heat exchanger system with exchanger arranged inside fairing that is entirely situated in rear with respect to engine mount - Google Patents

Abstract

The assembly has a heat exchanger system (104) comprising an outlet (122a) placed between a case (24) of a rigid structure of a pylon (4) and an engine. The outlet emerges out inside a rear aerodynamic fairing (66) of the pylon. The outlet is placed in rear with respect to a rear engine mount (8). The system has an exchanger (114) arranged inside the fairing that is entirely situated in rear with respect to the engine mount. The fairing has an air outlet opening with a controllable mobile structure permitting to modify an aerodynamic shape of the fairing.

Description

AIRCRAFT ENGINE ASSEMBLY COMPRISING AN ENGINE THUS

  THAT A MATT OF ATTACHING OF SUCH A MOTOR

DESCRIPTION TECHNICAL FIELD

  The present invention relates generally to the field of engine attachment poles intended to be interposed between an aircraft wing and a motor, and more particularly to an engine assembly comprising such a mounting pylon.

  The invention can be used on any type of aircraft equipped for example with turbojet engines or turboprop engines.

  This type of attachment pole, also known as EMS (Engine Mounting Structure), allows for example to suspend a turbine engine below the wing of the aircraft, or to mount the turbine engine above this same sail.

STATE OF THE PRIOR ART

  Such an attachment mast is in fact provided to form the connecting interface between an engine such as a turbojet engine and a wing of the aircraft. It makes it possible to transmit to the structure of this aircraft the forces generated by its associated turbojet, and also authorizes the routing of fuel, electrical, hydraulic and air systems between the engine and the aircraft.

  To ensure the transmission of forces, the mast has a rigid structure, also called primary structure, often of the box type, that is to say formed by the assembly of upper and lower spars and two side panels connected between them via transverse ribs.

  On the other hand, the mast is provided with a mounting system interposed between the turbojet engine and the rigid structure of the mast, this system generally comprising at least two engine fasteners, generally a front attachment and a rear attachment.

  In addition, the mounting system comprises a device for taking up the thrust forces generated by the turbojet engine. In the prior art, this device takes for example the form of two lateral rods connected on the one hand to a rear part of the turbojet fan casing, and on the other hand to the rear engine attachment fixed to the casing of this engine. latest.

  Similarly, the attachment mast also includes a second mounting system interposed between the rigid structure of the mast and the wing of the aircraft, the second system usually consisting of two or three fasteners.

  Finally, the mast is provided with a secondary structure ensuring the segregation and maintenance of the systems while supporting aerodynamic fairings, the lower rear aerodynamic fairing usually projecting from the trailing edge of the wing, rearward.

  In addition, the engine assembly is also equipped with a heat exchanger system. When the latter is of the conventional type, that is to say of the air / air type, it comprises an exchanger to which are connected a hot air intake, a cold air intake, a first outlet intended to be connected to a wing element of the aircraft, and a second exit opening above the rigid structure of the mast, upstream of the rear engine attachment. This particular arrangement of the second output has a certain number of disadvantages such as that requiring the provision of an outlet duct passing vertically through the rigid structure of the mast in order to bring the second exit above the latter, which gives rise to obvious problems of security, as well as implementation difficulties related to the poor accessibility to the box forming the rigid structure.

  In addition, with such an arrangement, the relatively hot air out of the second outlet near the wing of the aircraft, which substantially disturb the aerodynamic flow at the latter. The performance of the aircraft is therefore likely to be weakened by these disturbances.

  DISCLOSURE OF THE INVENTION The object of the invention is therefore to propose an engine assembly for an aircraft that at least partially overcomes the disadvantages mentioned above relating to the embodiments of the prior art, and also to present an aircraft having at least one such engine assembly.

  To this end, the subject of the invention is an engine assembly for an aircraft comprising a motor and an engine attachment pylon, this mast comprising on the one hand a rigid structure, also called primary structure, comprising a box preferably provided with a lower structural member such as a lower spar, and secondly a mounting system interposed between the engine and the rigid structure, the mounting system including a rear engine attachment, and the assembly being further provided a heat exchanger system comprising an exchanger to which a hot fluid intake is connected, a cold air intake, a first outlet for example intended to be connected to a wing element of the aircraft when the system of heat exchanger is of the air / air type, as well as at least a second output. According to the invention, each second output of the heat exchanger system is located between the box and the engine, therefore preferably below the lower spar structural member when the engine is intended to be suspended under the wing of the aircraft, each second output being arranged rearwardly relative to the rear engine attachment.

  Thus, this arrangement according to the invention does not advantageously require to provide a second outlet duct passing through the box of the rigid structure of the mast, since the second air outlet is located below the lower structural element of this box, as is also the case for the exchanger when the engine is intended to be suspended under the wing. The safety of the engine assembly and the ease of assembly of the heat exchanger system are therefore increased. On the other hand, the position specific to the present invention of the second outlet advantageously implies that the air which is extracted from it no longer disturbs the flow at the level of the wing. The performance of the aircraft can therefore be improved over those encountered with the achievements of the prior art.

  On the other hand, it must be understood that the second outlet opens beyond the rear engine attachment, at a level where the pressures are substantially higher than those encountered upstream of the engine attachment. Consequently, the pressure differential obtained between the cold air intake and the second outlet of the exchanger system is much greater than that previously encountered because of the strong suction encountered at this second outlet, which makes it possible to significantly increase the air flow through the exchanger system, and therefore increase the performance of the latter.

  Moreover, since the second output is at the rear of the rear engine attachment, it then becomes easy to unclog this output into the engine jet, and by the same to use the air ejected from this second output as an additional thrust generator.

  Preferably, the second outlet opens at the outer wall of a rear aerodynamic fairing of the attachment pylon, this rear aerodynamic fairing being located entirely rearward relative to the rear engine attachment.

  This configuration is extremely advantageous from the aerodynamic point of view. Indeed, the aforementioned fairing, also called shield or Aft Pylon Fairing and usually protruding rearward of a trailing edge of the wing, is generally impacted by the engine jet, resulting in a drag not negligible and relatively restrictive in terms of performance. Providing that this second outlet opens at the outer wall of the fairing allows to bathe the latter in an air space protecting it from the engine jet. Consequently, the drag generated by the reduced impact of the hot jet on the lower rear fairing is greatly reduced compared with that previously encountered, which advantageously induces performance gains.

  As such, in order to simultaneously increase the thrust generated by the air leaving the second output, improve the performance of the heat exchanger system, and enhance the protection of the rear aerodynamic fairing against the impact of the jet engine, one preferably this second outlet at a break / base of this fairing, so as to create an accentuated suction and thus to obtain an even higher pressure differential.

  An alternative to the above solution could consist in providing that the second outlet of the exchanger system opens inside the rear aerodynamic fairing of the attachment pylon. In such a case, it is then possible to provide an air outlet opening at the rear of this fairing to ensure the extraction of air, this opening possibly being able to be coupled to a controllable movable structure, which, depending on the its position makes it possible to modify the aerodynamic shape of said fairing. With such an arrangement where the movable structure is preferably placed through the opening, the control of the movable structure thus makes it possible to reduce / increase the suction of the air leaving the opening provided on this fairing, following that the latter is in a configuration defining one or more recesses to create a base effect to generate a significant air suction, or in a configuration defining a substantially continuous aerodynamic shape and without recess, to cause the least drag possible .

  Alternatively, still in the case where the second outlet of the exchanger system opens inside the rear aerodynamic fairing, it can be provided that the latter is equipped with a movable structure with two articulated side panels at their front end. , respectively on two side coverings of the fairing, each of the panels then being intended to close / release an opening made in its associated side coating of the fairing.

  It could also be provided two second outputs, one opening at the outer wall of the aerodynamic rear fairing of the attachment pylon, and the other opening inside this fairing, these two outputs can then be used alternately or simultaneously for the ejection of air.

  Preferably, the mast is made such that the rigid structure of the attachment pylon also comprises a structural block fixedly mounted on the box between the latter and the engine, and preferably under the lower structural element of the box when the engine is intended to be suspended under the wing of the aircraft, said structural block then said lower structural block having an attachment interface of the rear engine attachment.

  Thus, in the non-limiting case where the engine is intended to be suspended under the wings of the aircraft, this arrangement generally allows to deport the rear engine attachment downwardly relative to the box, thanks to the lower structural block is therefore part integral of the rigid structure and being assimilable to a bow or a hoof.

  The addition of this block with respect to the embodiments of the prior art in which the rigid structure was exclusively constituted by the box provides many advantages, including that of moving the same box of the engine suspended from the mast. Consequently, the thermal conditions experienced by this box are much smaller than those previously encountered in embodiments where the attachment interface of the rear engine attachment was located directly on the lower structural element of the lower spar type. This lightening of the thermal conditions therefore makes it possible to envisage the use of materials that are less sensitive to heat for the manufacture of the rigid box, such as composite materials. In such a case, it can advantageously result in a very significant mass gain for the entire mast attachment.

  In addition, it allows to separate the design of the structural block, mainly dictated by the need to ensure the passage of the forces from the rear engine attachment, that of the box, mainly sized according to the wing interface he supports. This feature implies that the width of the block may be smaller than that of the box, thus providing a considerable advantage in terms of aerodynamic performance, since it is the narrow block which is in the flow zone of the secondary stream. , and no longer the lower part of the box of higher width. The aerodynamic disturbances to the right of the rear engine attachment are thus greatly reduced compared to those previously encountered.

  On the other hand, it is understood that the geometry of the box is no longer influenced by the need to approach the crankcase, since this function can be entirely provided by the lower structural block attached fixedly on this box. The geometry of the latter can therefore be considerably simplified, as can its manufacture, in particular by providing a bottom face of the flat box from one end to the other of the rigid structure. Its mass is then reduced and perfectly optimized, insofar as the lower part of the casing advantageously has no larger width recess exclusively intended to approach the crankcase.

  Finally, it is indicated that the block projecting from the box downwards and extending only over a short longitudinal length of the rigid structure makes it easy to envisage passing pipes or similar elements through the same lower structural block. . This faculty offered to mast equipment thus facilitates access to the rear part of the rigid structure, which in the prior art, required to cross the box whose accessibility is relatively delicate. This faculty is particularly available to the heat exchanger system, which can therefore see its second output on a second output pipe connected to the exchanger and passing through the structural block, this solution then constituting a relatively simple way to bring this second output downstream of the rear engine attachment supported by the same block.

  Still preferentially, the first output of the heat exchanger system is provided on a first outlet duct connected to the exchanger and passing through the box of the rigid structure. This provision is entirely suitable in the case where the heat exchanger system is of the air / air type, and the first output is intended to be connected to a wing element of the aircraft.

  Nevertheless, it is noted that the invention also covers other cases in which the fluid passing through the heat exchanger system and exiting through the first outlet is intended to interest not the wing and / or the fuselage, but the engine, the nacelle, or on the rigid structure of the mast.

  As such, it is also noted that the heat exchanger system of the fluid / air type is such that the fluid passing through the hot fluid intake and the first outlet is taken from the group consisting of air, air and water. oil and fuel.

  In general, the exchanger is located between the box and the engine, forward relative to the rear attachment.

  Nevertheless, an alternative is to provide that the exchanger of the heat exchanger system is arranged at least partially within the rear aerodynamic fairing of the attachment pylon.

  In such a configuration that always makes it possible to use the ejected air of the second output as an additional thrust generator, one advantage lies in reducing the space between the front part of the box and the engine, which causes a reduction. disruptions in the ventilation of the same engine, and better accessibility in this area which is generally adjacent to the core area of the engine. In addition, the secondary flow is no longer disturbed by the presence of the exchanger in this area, which causes an increase in engine performance.

  In addition, in this case where the exchanger is therefore no longer located upstream of the rear engine attachment 10, the cold air intake can advantageously be located further back than previously, as for example at the level of a front part of the aforementioned fairing, so at a point where the pressures are higher. This allows the cold air to enter the exchanger system with a higher pressure, synonymous with gain in terms of performance for the same system.

  Finally, it is noted that in this case, the hot fluid intake of the heat exchanger system is provided on a hot fluid conduit connected to the exchanger and passing through the structural block of the rigid structure, so that this fluid intake It is preferable to attach the heat to the core zone of the engine, that is to say at the central casing of the latter. Of course, in the case where the fluid passing through the exchanger is not air but fuel or oil, the connection of this hot fluid outlet can be made at a location other than the core zone. of the motor.

  The invention also relates to an aircraft comprising at least one engine assembly such as that which has just been presented.

  Other advantages and features of the invention will become apparent in the detailed non-limiting description below.

BRIEF DESCRIPTION OF THE DRAWINGS

  This description will be made with reference to the appended drawings among which; - Figure 1 shows a side view of an engine assembly for aircraft according to a preferred embodiment of the present invention, the heat exchanger system of the box has been deliberately omitted for reasons of clarity; FIG. 2 represents an enlarged perspective view of the lower structural block belonging to the rigid structure of the attachment pylon of the engine assembly shown in FIG. 1; FIG. 3 represents a partial perspective view of the assembly of FIG. 1, showing the heat exchanger system; FIG. 4 shows a side view of an aircraft engine assembly, this assembly being in the form of an alternative of the preferred embodiment shown in FIGS. 1 to 3; FIGS. 5a and 5b respectively show a partial side view and a partial perspective view of an aircraft engine assembly in the form of another alternative of the preferred embodiment shown in FIGS. 1 to 3; FIGS. 6a and 6b show top views of a rear portion of the rear aerodynamic fairing of the suspension pylon belonging to the assembly shown in FIG. 3, more specifically showing a controllable movable structure capable of reducing / increasing suction of the air at the outlet of the fairing; - Figure 7 shows a view similar to those shown in Figures 6a and 6b, the movable structure being in an alternative embodiment; FIG. 8a represents a view similar to that shown in FIG. 4, with a rear aerodynamic fairing equipped with a steerable movable structure presented in another alternative form of embodiment; and - Figure 8b shows a sectional view taken along the line VIII-VIII of Figure 8a.

  DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, there is seen a motor assembly 1 for an aircraft intended to be fixed under a wing 3 of this aircraft, this assembly 1, provided with an attachment pylon 4, presenting itself in the form of a preferred embodiment of the present invention.

  Overall, the engine assembly 1 comprises a motor such as a turbojet engine 2 and the attachment pylon 4, the latter being in particular provided with a rigid structure 10 and a mounting system 11 composed of a plurality of engine fasteners 6, 8 and a thrust load recovery device 9 generated by the turbojet engine 2, the mounting system 11 is therefore interposed between the engine and the rigid structure 10 above. As an indication, it is noted that the assembly 1 is intended to be surrounded by a nacelle (not shown in this figure), and that the attachment pylon 4 comprises another series of fasteners (not shown) allowing ensure the suspension of this assembly 1 under the wing of the aircraft.

  Throughout the following description, by convention, X is the longitudinal direction of the mast 4 which is also comparable to the longitudinal direction of the turbojet engine 2, this direction X being parallel to a longitudinal axis 5 of the turbojet engine 2. Other On the other hand, Y is the direction transversely oriented with respect to the mast 4 and also comparable to the transverse direction of the turbojet 2, and Z is the vertical or height direction, these three directions X, Y and Z being orthogonal to one another.

  On the other hand, the terms front and rear are to be considered with respect to a direction of advancement of the aircraft encountered following the thrust exerted by the turbojet engine 2, this direction being represented schematically by the arrow 7.

  In Figure 1, it can be seen that only the recovery device 9, the engine fasteners 6, 8, and the rigid structure 10 of the attachment pylon 4 have been shown. The other non-represented constituent elements of this mast 4, such as the attachment means of the rigid structure 10 under the wing of the aircraft, or the secondary structure ensuring the segregation and maintenance of the systems while supporting aerodynamic fairings , are conventional elements identical or similar to those encountered in the prior art, and known to those skilled in the art. Therefore, it will not be done

  detailed description, except for fairing

  rear aerodynamic lower likely to have a feature related to the present invention.

  The turbojet engine 2 has at the front of a large fan casing 12 delimiting an annular fan duct 14, and comprises a rearward central casing 16 of smaller size, enclosing the heart of this turbojet engine. Finally, the central casing 16 is extended towards the rear by an ejection casing 17 of larger size than that of the casing 16. The housings 12, 16 and 17 are of course integral with each other.

  As can be seen in Figure 1, the plurality of engine fasteners is constituted by a front engine attachment 6 and a rear engine attachment 8 possibly forming two rear half-fasteners as known from the prior art. The recovery device 9 takes for example the form of two lateral rods (only one being visible due to the side view) connected on the one hand to a rear part of the fan casing 12, and on the other hand on a rudder 20, itself mounted on the rigid structure 10.

  The front engine attachment 6, secured to the bracket 15 of the rigid structure 10 and to the fan casing 12, is conventionally designed so as to be able to take up only the forces generated by the turbojet engine 2 along the Y and Z directions, and therefore not those forming in the direction X. As an indication, this front attachment 6 preferably penetrates into a circumferential end portion of the fan casing 12.

  The rear engine attachment 8 is generally interposed between the ejection housing 17 and the rigid structure 10 of the mast. As indicated above, it is preferably designed so as to be able to take up forces generated by the turbojet engine 2 along directions Y and Z, but not those acting in direction X. In this way, with the mounting system 11 of isostatic nature, the recovery of the forces exerted in the direction X is carried out using the device 9, and the recovery of forces exerted along directions Y and Z is carried out jointly with the help of the front attachment 6 and rear attachment 8.

  On the other hand, the recovery of the moment exerted in the direction X is carried out vertically with the aid of the fastener 8, the recovery of the moment being exerted in the direction Y is carried out vertically with the aid of the rear fastener 8 together with the fastener 6, and the recovery of the moment being in the direction Z is carried transversely with the aid of the fastener 8, together with the fastener 6.

  Still with reference to FIG. 1, it can be seen that the structure 10 firstly has a box 24 extending from one end to the other of this structure 10 in the X direction, and thus forms a torsion box said main box of the structure. It is conventionally formed by an upper spar 26 and a lower spar 28, as well as by two side panels 30 (only one being visible in Figure 1) both extending in the direction X and substantially in a plane XZ. Inside this box, transverse ribs 32 arranged in YZ planes and spaced longitudinally reinforce the rigidity of the box 24. It is noted as an indication that the elements 26, 28 and 30 can each be made of a single holding, or by the assembly of contiguous sections, which may possibly be slightly inclined relative to each other.

  Preferably, as clearly shown in Figure 1, the lower spar 28 is plane over its entire length, this plane being substantially parallel to an XY plane or slightly inclined relative to the latter.

  In this case where the engine is intended to be suspended under the wing, it is planned to fix, on the outer surface of the lower spar 28, a structural block 34 said lower structural block 34 due to its position under the box 24. Nevertheless, it is noted that in a case not described but covered by the present invention where the engine 2 would be mounted above the wing 3, the structural block would then be fixedly attached to the upper spar 26 of the box.

  The block 34 has an attachment interface 36 of the rear attachment 8, this interface 36 is therefore located below the plane in which the spar 28 is located, and preferably oriented along an XY plane. As will be described later, it is stated that this attachment interface 36 is intended to cooperate with a fastening body of the rear engine attachment 8.

  This solution in which the width of the block 34 in the direction Y is less than that of the box 24, therefore allows to move the clip 8 downwardly relative to the box 24, and thus to space the motor 2 of this latest.

  The thermal stresses applied to the box 24 are thus relatively low, so that it becomes possible to manufacture it in composite material, or in any other heat-sensitive material capable of generating a gain in terms of overall mass of the mast 4 On the other hand, the block 34 more exposed to these thermal stresses due to its proximity to the motor 2 can be made of a metallic material, preferably titanium.

  Referring now to Figure 2, it can be seen that the structural block 34 fixed below the lower spar 28 has generally two lateral flanks 40, each equipped in the upper part with a fastening fin 42 oriented according to the plane of the same spar 28 to contact the latter and to secure the block 34 on the box 24. In this respect, this attachment is preferably made via a plurality of traction bolts and shear pins (not shown ) arranged perpendicularly to the lower spar 28, along axes 44 passing through the fins 42. These fixing means advantageously reduce the thermal conduction between the block 34 and the lower spar 28, this conduction can be further reduced by inserting rings or insulating washers between these two elements 24, 34.

  On the other hand, the block 34 also comprises one or more transverse ribs 46 arranged between the two flanks 40, and preferably oriented along YZ planes.

  The attachment interface 36 is defined by a lower portion 50 of the two sidewalls 40, possibly in combination with one of the ribs 46 being preferably in the form of a frame. Thus, this fixing interface 36 formed by the two lower portions 50 of the sidewalls 40 and the lower part of the rib 46 in question constitute generally a horizontal band extending in the direction Y on which is fixed the fastening body 38 of the rear engine attachment 8, preferably via bolts.

  This attachment body 38 is of known type and design substantially identical to that previously encountered in the embodiments in which the body was mounted directly on the lower spar 28 of the box. Thus, it defines clevises 52 on which are articulated shackles (not shown) also intended to be articulated on integral motor brackets.

  In addition, an attachment fitting 54 of the spreader 20 is also arranged between the two lateral flanks 40, preferably forwardly relative to the fastening body 38. This fitting 54 then carries a pivot 56 of the spreader 20, itself hinged at both ends with the two connecting rods 9 of the thrust forces.

  Finally, it is indicated that this block 34 can take the form of a secondary rigid box, and incorporate front and rear closure plates (not shown) integral with the sidewalls 40, respectively closing this box forward and towards the back.

  With reference to FIG. 3, it can be seen that the engine assembly 1 furthermore comprises a heat exchanger system 104, which is generally constituted by means of a cold air intake 106 and an intake of hot air 108, the cold air intake 106 being preferentially arranged under the caisson 24, upstream of a junction between a blower part and a thrust reversal part of the nacelle (not shown), and more precisely at the outlet of the channel annular blower so as to be fed by the fresh air leaving it. The hot air intake 108 is connected directly to the central casing of the engine 2 (not shown). These cold air intake 106 and hot air intake 108 are respectively provided at the front end of a cold air duct 110 and a hot air duct 112, both connected by the intermediate their other end to a heat exchanger 114 located between the box 24 and the engine 2, upstream of the rear attachment 8 and the structural block 34. It is noted that the exchanger 114 has any known design of the skilled person.

  On the other hand, the system 104 includes a first outlet 116 intended to be connected to the wing, so as to provide the functions of defrosting, cabin air conditioning, etc. This outlet 116 is arranged at the end of a first outlet duct 120, the other end of which is connected to the exchanger 114. In order to be able to join the flange, provision is made for this duct 120 to pass through the casing 24, preferably vertically as shown in Figure 3.

  Finally, the exchanger system 104 is equipped with a second outlet 122a arranged at the end of a second outlet duct 124 whose other end is also connected to the exchanger 114.

  FIG. 3 also shows a thermal protection system 58 of the box 24, generally comprising a preferentially ventilated duct 60 running under the lower spar 28. However, this thermal protection system 58 does not form part of the present invention and therefore will not be described further.

  One of the peculiarities of the invention lies in the fact that the second outlet 122a is arranged rearwardly with respect to the fastener 8, under the spar 28 of the box 24 in the case where the motor is intended to be suspended under the wing of the aircraft. To do this, as can be seen in Figure 3, it is expected that the duct 124 passes longitudinally through the structural block 34, which is relatively simple to implement because of the short length of the block 34 in the direction X. In this same Figure 3, it has been shown one of the aerodynamic fairings equipping the mast 4, which is more specifically known as the rear aerodynamic fairing or lower rear aerodynamic fairing, or shield or Aft Pylon Fairing. This fairing 66, preferably arranged under the casing 24, is located entirely rearwardly relative to the fastener 8, and usually protrudes rearwardly from a trailing edge of the wing 3. It is therefore not part of the rigid structure of the mast, but is connected thereto by a support bracket 68 fixedly mounted under the housing 24, rearwardly relative to the block 34. In known manner, its lower front portion substantially tangent an upper portion of the exhaust nozzle of the engine 2.

  In this preferred embodiment, the duct 124 is such that it extends beyond the block 34 until it penetrates inside the fairing 66, so that the second outlet 122a of this duct is for example located close to a front portion of the fairing 66. To do this, before entering the shroud 66, the conduit 124 then passes through the fitting 68 supporting the same fairing.

  In Fig. 4 showing an alternate form of embodiment of the foregoing preferred embodiment, it can be seen that the second outlet conduit 124 does not fit within the shroud 66, but has a bend or bend downstream of the block 34 allowing him to follow the support bracket 68 downwards.

  Another bend or other curvature is provided so that an end portion of this conduit 124 can travel between the lower front portion of the fairing 66 and the upper portion of the exhaust nozzle 70. Thus, provision is made for that the second outlet 122b opens out at the outer wall of the fairing 66, preferably on a lateral or lower part thereof, and downstream of an ejection end 72 of the nozzle 70. In addition, the second 122b is preferably arranged at a break / recess (not shown) formed on the outer wall of the fairing 66, so as to create a base effect and thus an increased suction air out of the duct 124, which of course makes it possible to obtain a high pressure differential as well as an increase in the performance of the exchanger system 104.

  In addition, it is recalled that the particular positioning of the second outlet 122b at the outer wall of the fairing 66 makes it possible to bathe the latter in an air space protecting it from the jet of the engine, which advantageously implies a reduction of the drag caused by the impact of the hot jet on this fairing 66.

  Since the air extracted from the second outlet duct 124 is advantageously used to generate thrust, the case described above in which the second outlet 122a opens into the fairing requires the presence of an outlet opening of air on it.

  With reference to FIGS. 6a and 6b, it is possible to see a first way of producing the rear portion of the aerodynamic fairing 66, which is then provided with said air outlet opening 86 in its rear end portion.

  In this embodiment, it can be seen that the opening 86 is coupled to a controllable movable structure 88, which, as a function of its position, makes it possible to modify the aerodynamic shape of the fairing 66. Indeed, this structure 88 preferably takes the form of an ogive or the like, which when it occupies a rear position said aerodynamic deployed position, protrudes from the opening 86 so as to be located substantially in the aerodynamic extension of the side coverings 90a, 90b of the shroud 66, as is visible in Figure 6a. This structure 88, which is controllable in translation along a direction 92 preferably substantially parallel to the direction X, for example by means of actuating means 96 being connected thereto, thus makes it possible to obtain a fairing 66 of substantially aerodynamic shape. continuous and without offset, which generates a small drag. As an indication, this aerodynamic position will be preferentially adopted during the high speed phases of the aircraft.

  In FIG. 6b showing the mobile structure 88 in a position before said retracted suction position, it can be seen that this structure 88 is almost completely retracted with respect to the opening 86 which then has a larger section, which implies in particular that the aerodynamic extension of the side coverings 90a, 90b of the shroud 66 is no longer ensured. On the contrary, a detachment or aerodynamic rupture 98a, 98b appears at the rear end of each of these two coatings 90a, 90b, which generates base effects caused by the air licking the outer wall of these coatings 90a, 90b. These base effects thus ensure an increase in the suction of the air leaving the opening 86, thereby favoring the effectiveness of the protection system 58.

  Therefore, this suction position will be preferentially adopted during the low speed phases of the aircraft. Indeed, at low speed, the drag caused by the recesses 98a, 98b is not penalizing, and the suction created by them makes it possible to increase the differential pressure, which, without the presence of these recesses, would be d a low value due to the low speed of the aircraft.

  Referring now to Figure 7, there is a second way of providing the rear portion of the aerodynamic fairing 66, which is also provided with the air outlet opening 86 in its rear end portion.

  In this embodiment, we see that the opening 86 is coupled to a movable structure 88 which no longer takes the form of an ogive, but two panels 100a, 100b articulated with respect to one another at their level. rear end along an axis 102 preferably parallel to the direction Y, these panels 100a, 100b permanently projecting from the opening 86.

  In the separated position represented in solid lines, said aerodynamic extended position, the two panels 100a, 100b have a front end bearing against the rear end of the lining 90a, 90b of the shroud 66, so as to be located substantially in the aerodynamic extension of these. This structure 88, which is therefore rotatable about the axis 102, for example by means of the actuating means 96 connected thereto, thus makes it possible to obtain a fairing 66 of substantially continuous aerodynamic shape and without recess, which generates a small drag.

  In the close position called the retracted suction position shown in dashed lines in FIG. 7, it can be seen that the two forward ends of the panels 100a, 100b which have been brought together by pivoting are respectively very far from the rear ends of the covers 90a, 90b, notably implying that the opening 86 has a larger section, but especially that the aerodynamic extension of these side coverings 90a and 90b of the shroud 66 is no longer ensured. On the contrary, a detachment or aerodynamic rupture 98a, 98b appears between the rear end of each of these two coatings 90a, 90b and its associated panel 100a, 100b located further back, which generates the effects of pellet caused by the air licking the outer wall of these coatings 90a, 90b.

  In the two alternatives which have just been described, an advantage related to such use is to be able to benefit from an opening 86 of variable section depending on the position of the mobile structure 88. Indeed, the possible regulation of the quantity air leaving the second outlet by varying the section of the opening of the fairing allows to remove the valve provided for the same purpose which was previously placed upstream on the exchanger system.

  Referring now to Figures 8a and 8b, there is a third way of ensuring the ejection of the air out of the aerofoil fairing 66, without it being provided with an outlet opening in its portion of rear end, but two openings 105a, 105b located on either side of the fairing 66, respectively on the two side coatings 90a, 90b of the latter. As an indication, these openings 105a, 105b may be located in or near a central zone of the shroud 66, considered in the direction X. Indeed, in this embodiment, we see that the mobile structure 88 generally takes the form of two side panels / flaps 101a, 101b each hinged at its front end on a side coating 90a, 90b of the shroud 66, respectively along axes 103a and 103b preferably parallel to the Z direction. In the folded position shown in solid lines , said aerodynamic position, the two panels 101a, 101b have a rear end resting against the coverings 90a, 90b of the shroud 66, so as to be located substantially in the aerodynamic extension of the latter. This structure 88, which is therefore rotatable, for example by means of actuating means (not shown) being connected thereto, thus makes it possible to obtain a fairing 66 of substantially continuous aerodynamic shape and without recess, which generates a drag not important. In this folded position, each of the side panels 101a, 101b thus closes its associated aperture 105a, 105b made in the relevant lateral coating 90a, 90b of the fairing.

  In the deployed position called air ejection position shown in dashed lines in Figure 8b, it can be seen that the two rear ends of the panels 101a, 101b which have been pivotally spaced along the axes 103a, 103b are respectively remote from the coating 90a, 90b, implying in particular that the aerodynamic extension of these side coverings 90a and 90b of the shroud 66 is no longer ensured, but especially that the air located in the shroud 66 can escape through the free spaces created between the coatings 90a , 90b and the rear ends of the side panels 101a, 101b. The spacing of the panels / side flaps 101a, 101b, which therefore results in a release of the openings 105a, 105b mentioned above, is also naturally likely to cause an advantageous suction effect, when they are deployed.

  This solution panels / side flaps 101a, 101b is particularly retained when it is decided to implement jointly the two outputs 122a and 122b, as shown schematically in Figure 8a.

  A suitable system (not shown) can then make it possible to favor the ejection of air either by the outlet 122a, or by the outlet 122b, or by these two last simultaneously. In this regard, it is noted that the output 122a will preferably be used in case of failure and for high data rates (low speeds of the aircraft), while the output 122b will preferably be used in cruising or for low speeds (high speeds of the aircraft).

  In FIGS. 5a and 5b showing an assembly 1 in the form of another alternative for producing the motor assembly 1, it can be seen that the main difference in design with the assemblies of FIGS. 3 and 4 consists in providing the exchanger 114 at least partially inside the shroud 66, therefore downstream of the block 34 and the rear fastener 8. Therefore, it is no longer the second outlet duct that passes through the structural block 34, but the duct of hot air 112 carrying the hot air intake 108 attached to the central casing 16 of the engine 2. It is also specified that the hot air duct 112 may carry an additional hot air intake 108b, also reported on the motor 2, back from the socket 108. It is specified in this regard that each of the preferred embodiments could be equipped with this additional hot air intake, without departing from the scope of the invention.

  On the other hand, the first outlet duct is always placed so as to traverse the well 24 vertically, but downstream of the block 34, as can clearly be seen in Figures 5a and 5b.

  Finally, the cold air intake 106 and the second outlet 122 are located laterally on either side of the exchanger 114, behind the rear attachment 8, as is also seen in Figures 5a and 5b.

  Naturally, the arrangements shown in FIGS. 6a, 6b, 7 and 8b can be implemented on the fairing 66 of the motor assembly 1 shown in FIGS. 5a and 5b.

  Of course, various modifications may be made by those skilled in the art engine assemblies 1 for aircraft that have just been described, only by way of non-limiting examples. In this regard, it is possible in particular to indicate which if the mast 4 has been presented in a configuration adapted to be suspended under the wing of the aircraft, this mast 4 could also be in a different configuration allowing it to be mounted above this same sail.

  Furthermore, the heat exchanger system used in the present invention could be of a type other than air / air, namely fuel / air or oil / air, without departing from the scope of the invention.

Claims (11)

  1. Engine assembly (1) for an aircraft comprising a motor (2) and a latching pylon (4) of the engine, said mast comprising on the one hand a rigid structure (10) comprising a box (24) and other a mounting system (11) interposed between the motor (2) and said rigid structure (10), said mounting system (11) comprising in particular a rear engine attachment (8), said assembly being further provided with a system heat exchanger assembly (104) having an exchanger (114) to which a hot fluid inlet (108), a cold air intake (106), a first outlet (116) and at least a second outlet ( 122), each second outlet (122) of the heat exchanger system (104) being located between said housing (24) and the engine (2), characterized in that each second outlet (122) is located rearwardly relative to to said rear engine attachment (8), and in that said exchanger (114) of the heat exchanger system (104) is arranged at the ego ns partially within a rear aerodynamic fairing (66) of the pylon (4), said rear aerodynamic fairing (66) being located entirely rearward of said rear engine mount (8).   2. Engine assembly (1) according to claim 1, characterized in that said second outlet (122) opens into said rear aerodynamic fairing (66) of the attachment pylon (4).   3. Engine assembly (1) according to claim 2, characterized in that said rear aerodynamic fairing (66) comprises an air outlet opening (86) equipped with a steerable movable structure (88), which, depending on its position makes it possible to modify the aerodynamic shape of said fairing (66).   4. Engine assembly (1) according to claim 3, characterized in that said movable structure (88) is placed through said air outlet opening (86).   5. Engine assembly (1) according to claim 2, characterized in that said rear aerodynamic fairing (66) is equipped with a movable movable structure (88) having two side panels (101a, 101b) hinged at their front end. respectively on two side coverings (90a, 90b) of the fairing (66), each of said panels (101a, 101b) being intended to close / release an opening (105a, 105b) formed in its associated lateral coating (90a, 90b) of fairing (66).   6. Engine assembly (1) according to any one of the preceding claims, characterized in that said rigid structure (10) of the attachment pylon (4) also comprises a structural block (34) fixedly mounted on said housing (24) between the latter and said engine (2), this structural block (34) having an attachment interface (36) of said rear engine attachment (8).   7. Motor assembly (1) according to any one of the preceding claims, characterized in that said first outlet (116) of the heat exchanger system (104) is provided on a first outlet duct (120) connected to the exchanger (114) and passing through said box (24) of the rigid structure (10).   8. Engine assembly (1) according to claim 7, characterized in that said first outlet (116) is intended to be connected to a wing element (3) of the aircraft.   9. Engine assembly (1) according to any one of the preceding claims combined with claim 6, characterized in that said hot fluid intake (108) of the heat exchanger system (104) is provided on an air duct hot (112) connected to the exchanger (114) and passing through said structural block (34) of the rigid structure (10).   10. Engine assembly (1) according to any one of the preceding claims, characterized in that said heat exchanger system (104) is of the fluid / air type, the fluid passing through the hot fluid intake (108) and said first outlet (116) and being selected from the group consisting of air, oil and fuel.   11. Aircraft characterized in that it comprises at least one engine assembly (1) according to one   any of the preceding claims.