Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
  • F02K1/06—Varying effective area of jet pipe or nozzle
  • F02K1/12—Varying effective area of jet pipe or nozzle by means of pivoted flaps
  • F02K1/1261—Varying effective area of jet pipe or nozzle by means of pivoted flaps of one series of flaps hinged at their upstream ends on a substantially axially movable structure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
  • F02K1/54—Nozzles having means for reversing jet thrust
  • F02K1/64—Reversing fan flow
  • F02K1/70—Reversing fan flow using thrust reverser flaps or doors mounted on the fan housing
  • F02K1/72—Reversing fan flow using thrust reverser flaps or doors mounted on the fan housing the aft end of the fan housing being movable to uncover openings in the fan housing for the reversed flow
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2260/00—Function
  • F05D2260/50—Kinematic linkage, i.e. transmission of position

Definitions

• the invention relates to a turbojet engine nacelle comprising a variable nozzle section.
• An aircraft is driven by several turbojets each housed in a nacelle also housing a set of ancillary actuators related to its operation and providing various functions when the turbojet engine is in operation or stopped.
• These ancillary actuating devices comprise in particular a mechanical system for actuating thrust reversers.
• a nacelle generally has a tubular structure comprising an air inlet upstream of the turbojet engine, a median section intended to surround a fan of the turbojet engine, a downstream section housing a thrust reverser means and intended to surround the combustion chamber of the turbojet engine. , and is generally terminated by an ejection nozzle whose output is located downstream of the turbojet engine.
• the modern nacelles are intended to house a turbofan engine capable of generating through the blades of the rotating fan a flow of hot air (also called primary flow) from the combustion chamber of the turbojet engine, and a flow of cold air (secondary flow) flowing outside the turbojet through an annular passage, also called vein, formed between a shroud of the turbojet engine and an inner wall of the nacelle.
• the two air flows are ejected from the turbojet engine from the rear of the nacelle.
• the role of a thrust reverser is, during the landing of an aircraft, to improve the braking capacity thereof by redirecting forward at least a portion of the thrust generated by the turbojet engine.
• the inverter obstructs the cold flow vein and directs the latter towards the front of the nacelle, thereby generating a counter-thrust which is added to the braking of the wheels of the aircraft.
• the means implemented to achieve this reorientation of the cold flow vary according to the type of inverter.
• the movable cowl belongs to the rear section and has a downstream side forming an ejection nozzle for channeling the ejection of the air flows.
• This nozzle can come in complement of a primary nozzle channeling the hot flow and is then called secondary nozzle.
• the mobile cowl is thus equipped, as is known from document US Pat. No. 5,806,302, with at least one nozzle movable relative to said movable cowl, so as to adjust the ejection section of the annular channel as a function of the position of said nozzle .
• the mobile nozzle is also referred to as the movable structure for adjusting the nozzle section.
• Each moving part namely the reverse thrust cover on the one hand, and the movable nozzle on the other hand, is actuated by a dedicated actuator.
• the French application FR 06/05512 also describes a variable nozzle system associated with a gate inverter and whose external structure completely completes the external lines of the inverter.
• This application discloses the use of a telescopic jack with a first rod is intended to actuate the movable cover while the second rod is intended for adjusting the nozzle.
• Such a system makes it possible to respond to the problem of the centralization of the supply and control means at a front frame on which is fixed the base of the double action actuator.
• variable nozzles thus has a relatively complex structure and requires an additional actuation system impacting the reliability and mass of the entire nacelle.
• the present invention therefore aims to provide a simplified structure and does not require a dedicated actuating member.
• the present invention relates to a nacelle of a turbofan engine comprising a downstream section, equipped with a thrust reverser device comprising a movable cowl mounted in translation in a direction substantially parallel to a longitudinal axis of the nacelle.
• said mobile cowl also being extended by at least one nozzle section mounted at a downstream end of said movable cowl, characterized in that the nozzle section comprises at least one panel mounted to rotate about at least one pivot axis substantially perpendicular to a longitudinal axis of the nacelle, said panel being further linked to a fixed fairing structure of the turbojet engine by at least one rod mounted to rotate around anchor points respectively on the panel of the nozzle section and on the fixed structure.
• connection rods depends on the loadings and balancing caused by the panels concerned.
• two connecting rods placed laterally or at each near a lateral edge of the nozzle section may be provided.
• the connecting rod is mounted obliquely such that an end of said rod connected to the panel is upstream of an end connected to the fixed structure when the panel is in the cruising position, causing an increase in the nozzle section during the retraction of the movable hood.
• the rod is mounted obliquely such that an end of said rod connected to the panel is downstream of an end connected to the fixed structure when the panel is in the cruising position, resulting in a reduction of the nozzle section during the retraction of the movable hood.
• the nacelle comprises between four and six pivoting panels of movable nozzle section.
• the number and length of the panels depends on the expected performance objectives and is not the same as six panels.
• the number of six panels optimizes the aerodynamic loss due to the connecting rods in the flow vein of the air flow.
• the articulation of the panel of the pivoting nozzle section is defined in the thickness of aerodynamic lines of the downstream end of the mobile pot.
• the thickness of the aerodynamic elements is not sufficient, it is possible to provide an overflow said lines with a combination of aerodynamic fairing internally or externally depending on the selected kinematics.
• each panel is articulated around two connecting rods each connected to said panel of the nozzle section via a point of articulation, the two points of articulation being spaced apart by a distance corresponding substantially to two thirds of the width of said panel of the movable nozzle section.
• At least a portion of the nozzle section has a downstream trimming forming chevrons.
• the downstream clipping can also be smooth or coplanar.
• the movable hood is extended by a fixed section on each side of each panel of the movable nozzle section, said fixed section being designed to ensure the continuity of aerodynamic lines of the downstream section when the panel of the nozzle section is located. in a cruising position.
• the presence of such intervolets extensions allows to respect the aerodynamic lines of the nacelle in cruising position.
• the intervolets thus formed by the fixed sections can be reduced to their simplest expression or even deleted and leave only the nozzle section panels in contact with each other.
• said fixed section has at least one lateral shoulder designed to support the panel of the movable nozzle section.
• the fixed section comprises sealing means with each corresponding movable nozzle section panel.
• the connecting rod of the nozzle section panel to a shroud structure of the turbojet engine is adjustable in length.
• the length of the connecting rod can be precisely adapted to the desired amplitude of rotation as a function of the displacement of the movable cowl.
• At least one anchor point of the connecting rod of the nozzle section panel to a shroud structure of the turbojet engine is adjustable according to at least one axial direction of the rod, and possibly in longitudinal and transverse directions of the nacelle.
• FIG. 1 is a diagrammatic representation in longitudinal section of a thrust reversal structure equipped with a pivoting nozzle section according to the invention.
• Figure 2 is a schematic cross-sectional representation of an ejection section of a nacelle according to the invention comprising a plurality of pivoting nozzle sections.
• Figures 3 and 4 are side views corresponding to Figure 2, respectively having nozzle sections in the cruising position and in the open position.
• FIG. 5 is an enlarged schematic representation of an area of FIG.
• FIGS. 6 to 9 are diagrammatic representations in longitudinal section of the thrust reversal structure of FIG. 1, respectively in a recoil position, a retracted position, an inverter opening position, and an advanced position of the inverter.
• Figures 10 to 12 are enlarged partial views of a junction zone between the movable cover of the thrust reverser and a front frame of the nacelle.
• a nacelle is intended to constitute a tubular housing for a turbofan engine (not shown) with a large dilution ratio and serves to channel the air flows it generates through the blades of a fan (not shown). That is, a flow of hot air passing through a combustion chamber (not shown) of the turbojet engine, and a cold air flow circulating outside the turbojet engine (F).
• a nacelle generally has a structure comprising a front section forming an air inlet, a central section surrounding the fan of the turbojet, and a downstream section surrounding the turbojet and may include a thrust reversal system.
• the downstream section comprises an external structure possibly comprising a thrust reversal system and an internal engine fairing structure 2 defining with the external surface a vein 3 intended for the circulation of a cold flow F in the case of a turbojet engine nacelle as discussed herein.
• Figure 1 is a schematic representation in longitudinal section of a downstream section equipped with a thrust reversal structure and a pivoting nozzle section according to the invention.
• This downstream section comprises a front frame 5, a moving thrust reverser cowl 6, and a nozzle section 7.
• the downstream section comprises two half-parts each equipped with a movable cover 6.
• the movable cover 6 is able to be actuated in a substantially longitudinal direction of the nacelle between a closed position in which it comes into contact with the frame before 5 and ensures aerodynamic continuity of the lines of the downstream section, and an open position in which it is spaced from the front frame 5, thus revealing a passage in the nacelle and discovering deflection grids 70.
• the moving cowl 6 rotates a flap 8 via a connecting rod 9 fixed in the inner fairing structure 2, said shutter from partially closing off the vein 3 so as to optimize the inversion of the air flow F.
• the nozzle section 7 comprises a plurality of peripheral panels pivotally mounted at a downstream end of the movable cowl 6.
• the downstream section comprises six movable panels 10 distributed on the periphery of the nozzle. said section, three panels 10 being associated with the movable cover 6 of the right half-part and three panels 10 being associated with the movable cover 6 of the left half-part.
• Each panel 10 is connected by a connecting rod 11 to the inner fairing structure 2.
• the rod 1 1 ensures the pivoting of the corresponding panel 1 0.
• the displacement of the movable cowl 6 thus allows the adjustment of the panels 10 of the nozzle section 7 without requiring the implementation of a dedicated actuating means and control system.
• the movable cover 6 must be able to be moved slightly upstream and downstream without causing inversion or leakage of the flow F.
• the invention is illustrated by an example in which the rod 11 for actuating the panel 10 is oblique and whose end connected to the panel is located upstream of the end of the bed to the internal structure 2 when the nozzle section is in cruising position, it is possible to reverse the orientation of said rod. In the latter case, a retreat of the movable hood 6 will reduce the nozzle section instead of an increase as in the case described.
• the movable hood 6 has an upstream extension 15 extending above an upper shoulder 16 of the front frame 5 on which it can be moved without opening any space in the downstream section.
• a seal 17 disposed between the extension 15 and the upper shoulder 16 ensures the absence of leakage of the flow F.
• each panel 10 is surrounded by a fixed section 18 extending the movable cover 6 and providing aerodynamic continuity of the downstream section when the panels 10 are in the cruising position.
• These fixed sections 18 each have lateral shoulders 19 capable of serving as supports for the panels 10. These lateral shoulders 19 may advantageously be equipped with seals.
• Figures 6 to 9 show different maneuvering positions of the panels 10 and the movable cover 6.
• the panels 10 may have returned to a position close to their direct jet cruise position.
• the movable cowl 6 is over-retracted, that is to say maneuvered upstream beyond its normal closed position, which causes the panel 10 to pivot towards the inside of the vein, and therefore a reduction of the nozzle section.
• the rod 1 1 has a significant impact on the pivoting of the corresponding panel 10.
• the slightest movement of the movable cowl 6 acts on the rotation of the panels 10.
• the rod 1 1 may be provided adjustable, in length, and / or longitudinally or transversely.
• the adjustment of the connecting rod in length can be carried out by means of the connecting rod itself or by adjusting the anchoring points on the panels 10 and the internal structure 2 fairing.
• FIGS. 10 to 12 show different variants of embodiment of the upstream seal between the movable cover 6 and the front frame 5.
• FIG. 10 shows a seal 11 placed below the deflection grids 70 towards the inside of the downstream section .
• Such an arrangement makes it possible not to pressurize the inside of the movable cowl 6.
• FIG. 11 shows an active upstream seal comprising a seal 217 mounted on an elastic return means 218 which keeps it in contact with the front frame over the entire adjustment distance.
• An advantage of this system lies in the quality of crushing of the seal 217 which is direct and continuous and no longer sliding as in the case of the seal 17.
• FIG. 12 shows another alternative embodiment of an active upstream seal, this time arranged below the deflection grids 70, which makes it possible not to pressurize the inside of the movable cover 6.
• This sealing system comprises a seal 317 mounted on an elastic member 318 carried by an inner portion of the movable cover 6.
• the resilient member 318 maintains the seal 317 against the front frame 5 during the adjustment phase of the nozzle section.
• the invention is not limited to the embodiments of this nacelle, described above as examples, but it embraces all variants.
• the mobile nozzle could be associated with a smooth nacelle and not with a nacelle equipped with a thrust reverser.

Applications Claiming Priority (2)

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Citations (1)

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• 2008
  • 2008-04-14 FR FR0802036A patent/FR2929998B1/fr not_active Expired - Fee Related
• 2009
  • 2009-04-09 CN CN2009801130527A patent/CN102007284A/zh active Pending
  • 2009-04-09 WO PCT/FR2009/050643 patent/WO2009136096A2/fr active Application Filing
  • 2009-04-09 BR BRPI0910935A patent/BRPI0910935A2/pt not_active IP Right Cessation
  • 2009-04-09 EP EP09742294A patent/EP2268910A2/de not_active Withdrawn
  • 2009-04-09 CA CA2719155A patent/CA2719155A1/fr not_active Abandoned
  • 2009-04-09 US US12/937,462 patent/US20110030338A1/en not_active Abandoned
  • 2009-04-09 RU RU2010145242/06A patent/RU2499904C2/ru not_active IP Right Cessation

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