Turbojet engine nacelle with variable ventilation outlet cross section

Abstract

A turbojet engine nacelle includes a rear section having an internal structure. The internal structure surrounds a rear part of an engine compartment and delimits, with an ejection jet pipe, an outlet cross section for the ventilation of the engine compartment. The engine nacelle includes a moving element associated with a corresponding controller. The moving element is able to move between a withdrawn position in which the outlet cross section for ventilation is at a maximum and an engaged position in which the moving element partially reduces the outlet cross section for ventilation by comparison with the retracted position. The controller is capable of moving the moving element between the retracted and engaged positions.

Claims

1. A turbojet engine nacelle comprising a rear section having an inner structure surrounding a rear part of an engine compartment and having a ventilation compartment, the inner structure configured to delimit, with a jet nozzle, a ventilation outlet cross-section of the ventilation compartment, wherein the turbojet engine nacelle comprises at least one moving element associated with at least one corresponding control device, said moving element being disposed within the ventilation compartment and movable between a retracted position in which the ventilation outlet cross-section is maximal, and an engaged position in which the moving element at least partially reduces the ventilation outlet cross-section relative to the retracted position, said control device comprising an actuator being operable to move the moving element between the retracted and engaged positions, and said moving element being biased in the retracted position by a biasing member, the actuator being spaced apart from the biasing member.

2. The nacelle according to claim 1, wherein the moving element can be moved into at least one intermediate position between its retracted and engaged positions.

3. The nacelle according to claim 2, wherein the moving element can be moved continuously between its retracted and engaged positions.

4. The nacelle according to claim 1, wherein the moving element is rotatably mounted around a pivot axis.

5. The nacelle according to claim 1, wherein the moving element is movably mounted on an exhaust shroud at the jet nozzle.

6. The nacelle according to claim 1, wherein the moving element is made in several sectors and extends over at least part of a periphery of the ventilation outlet cross-section.

7. The nacelle according to claim 1, wherein the moving element is made in a single sector that is at least partially peripheral.

8. The nacelle according to claim 1, wherein the actuator of the movable element comprises at least one electric driving device.

9. The nacelle according to claim 1, wherein the actuator of the moving element comprises at least one of a pneumatic and hydraulic driving device.

10. The nacelle according to claim 1, wherein the actuator is a push-piece and the biasing member is a return spring.

Description

DRAWINGS

(1) In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

(2) FIG. 1 is a diagrammatic longitudinal cross-sectional view of the nacelle according to the present disclosure in the closed state,

(3) FIG. 2 is a partial enlarged diagrammatic view of a rear section of the nacelle of FIG. 1,

(4) FIG. 3 is a partial diagrammatic perspective view from the rear of the nacelle of FIG. 1,

(5) FIG. 4 is a partial longitudinal cross-sectional view of a moving element equipping a ventilation outlet of the nacelle of FIG. 1 according to the present disclosure,

(6) FIG. 5 is a cross-sectional and partially enlarged detailed view of an outlet section and a rail/guideway system of a nacelle according to the teachings of the present disclosure, and

(7) FIGS. 6 to 13 are partial diagrammatic and longitudinal cross-sectional views of alternative forms of the moving element equipping a ventilation outlet of a nacelle according to the present disclosure.

(8) The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

(9) The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

(10) A nacelle 1 of an aircraft according to the present disclosure, as diagrammatically shown in FIG. 1, comprises, in a known manner, a front air intake section 2, a middle section 3 designed to surround the fan (not visible), and a rear section 4 designed to surround an engine compartment 5 and ending with a jet nozzle 6 whereof the outlet is situated behind the turbojet engine.

(11) This nacelle 1 comprises an outer structure 7, called OFS (Outer Fixed Structure), which defines an annular flow channel 8 with a concentric inner structure 9, called IFS (Inner Fixed Structure), surrounding a downstream part 5 of the turbojet engine behind the fan.

(12) By way of illustration, it will be noted that the outer structure of the downstream section 4 shown is equipped with a thrust reverser device. Of course, this may also be a nacelle not equipped with a thrust reverser device, called a smooth structure.

(13) The inner structure 9 defines a ventilation compartment 10 around the turbojet engine 5, allowing the circulation of a flow of cooling air (Arrows) around the turbojet engine by taking air from the tunnel 8.

(14) The air taken is discharged from the ventilation compartment 10 through a ventilation outlet 11, delimited by a separation between the inner structure 9 and the jet nozzle 6 and maintained by separating means (not visible).

(15) According to the present disclosure and like one form shown in FIGS. 4 and 5, the nacelle 1 comprises at least one moving element 15, associated with at least one corresponding control means (not visible), said moving element 15 being movable between a retracted position in which the ventilation outlet cross-section 11 is maximal, and an engaged position in which the moving element 15 at least partially reduces the ventilation outlet cross-section 11 relative to the retracted position, said control means being able to move the moving element 15 between the retracted and engaged positions.

(16) The outlet cross-section 11 can therefore be actively and dynamically controlled to regulate the air pressure in the ventilation compartment 10 and to adapt to overpressure or pressure decrease cases.

(17) The moving element can be designed to adopt one or more discrete positions between its retracted position and its engaged position, or to be moved continuously along a travel path.

(18) As shown in FIG. 5, it should be noted that as a general rule, the outlet cross-section 11 does not extend over the entire periphery of the nozzle 6 and the inner structure 9, an upper portion being made sealable for fire packaging reasons.

(19) The moving element 15 can be made in a single piece or several sectors, which may optionally be independent.

(20) The shape of the moving element 15 may assume the desired form and may be adapted as a function of flow constraints in particular. It may in particular be incorporated into the enclosure of the structure 6, 9 on which it is mounted.

(21) It is thus, for example, possible to provide a beveled moving element 15, 155, 158, 159, a moving element 151, 152 with a substantially rectangular cross-section, a rounded moving element 153, a pivoting flap 154, 156, etc.

(22) According to one form, as shown in FIGS. 4, 6 to 9, the moving element 15, 151, 152, 153, 154 is movably mounted on an exhaust shroud at the jet nozzle 6.

(23) According to another from, as shown in FIGS. 10 to 12, the moving element 155, 156, 158 is movably mounted on the inner structure 9.

(24) According to still another form, as shown in FIG. 13, the moving element 159 is movably mounted independently between the inner structure 9 and a shroud of the jet nozzle 6.

(25) The movement of the moving element can also be of a different nature.

(26) According to a first alternative form (FIGS. 4, 6, 7, 10, 12 and 13), the moving element 15, 151, 152, 155, 158, 158 is translatably mounted.

(27) The guiding of the moving element may be done by means of a rail/guideway system, as shown in FIG. 5 (enlarged portion).

(28) The moving element may be movable along a substantially longitudinal axis of the nacelle, but also along a radial axis of the nacelle or a combination of the two.

(29) According to a second alternative form (FIGS. 9, 11), the moving element 154, 156 is rotatably mounted around a pivot axis like a check valve.

(30) Of course, these forms are not limiting and equivalent means known by those skilled in the art can also be used.

(31) The moving element 15 may be driven by any known actuating means, adapted to the surrounding temperature and pressure conditions.

(32) It is in particular possible to provide electric, or pneumatic or hydraulic driving means.

(33) Advantageously, the driving and/or control means will be offset from the moving element, in particular in a so-called cold zone, i.e., toward the upstream direction of the turbojet engine 5 and the ventilation compartment 10. In such a case, it is possible to provide driving by traction cable or rigid return such as a Cardan joint system.

(34) By way of complementary characteristics that may be generalized to the described forms, FIGS. 6 and 12 show the placement of local stops 161 positioned at the interface between the inner structure 9 and the nozzle shroud 6. The stops aim to make it possible to guarantee minimal separation between said inner structure 9 and the nozzle 6 in the case of relative deformation of the two structures 6, 9.

(35) FIGS. 8 and 9 show forms using pressure-sensitive driving means in the ventilation compartment 10.

(36) More specifically, FIG. 8 provides, as moving element 153, an inflatable element, like a bladder, which, by inflating, at least partially obstructs the ventilation outlet 11 more or less. One such type of system is particularly useful with control means of the pneumatic or hydraulic type. The pneumatic or hydraulic system may be associated with the engine or may be dedicated and autonomous. Furthermore, this inflatable element 153 can be elastic and tend to return automatically toward a default position, corresponding to a minimal or maximal outlet cross-section 11, in the event its supply pressure is released.

(37) The aspect of FIG. 9 shows a moving element 154, made in the form of a pivoting flap, mounted against a return spring 163 tending to return it toward a retracted position in which the outlet section 11 is maximal. This flap is actuated by a mechanical retractable push-piece 164. This push-piece may be electric, hydraulic or pneumatic. The actuation of the flap may be done upstream or downstream of its axis of articulation. Furthermore, one push-piece can drive several flaps.

(38) Likewise, FIG. 11 shows an elastic flap 156 (blade spring, for example) forced by a push-piece 157. The blade spring may have one end made up of several strips, for example formed by channels in the blade.

(39) In FIG. 12, the moving element 158 is guided on the inner structure 9 following a rectilinear movement in the axis of the nacelle. Such a configuration makes it possible to design a single-piece structure of the moving element 158.

(40) In FIG. 13, the moving element 159 is guided either on the inner structure IFS 9 or on the jet nozzle structure. The moving element 159, in its translation, reduces the passage section simultaneously between the two structures.

(41) Furthermore, in the case of a so-called D-Duct nacelle structure, i.e., whereof the outer structure OFS comprises two semi-cylindrical half-cowls articulated in an upper area at an attachment mast, the moving element 158 can be made continuously from a sector covering the upper area without ventilation to the lower area of the inner structure 9.

(42) In the case of a structure with a so-called O-duct downstream section 4, i.e., formed by a single substantially cylindrical sliding cowling, the moving element 158 may be formed by a sector connecting the two upper areas without ventilation.

(43) Although the present disclosure has been described relative to specific example forms, it is of course in no way limited thereto and encompasses all technical equivalents of the described means, as well as combinations thereof if they are within the scope of the disclosure.