Rotorcraft equipped with an aerodynamic device having a fairing provided with an air intake

Abstract

A rotorcraft having an aerodynamic device arranged below a rotor, which rotor participates at least in providing lift for the rotorcraft in the air, the rotor being mounted to rotate about a first axis of rotation, the aerodynamic device having a fairing provided with at least one air inlet for enabling a stream of cool air to flow from a region that is situated outside the rotorcraft to another region that is situated inside the rotorcraft; at least at a mouth of the at least one air inlet in the fairing, the aerodynamic device has at least one moving flap that is mounted to move in rotation, the at least one moving flap having at least one degree of freedom of movement in rotation about a second axis of rotation relative to the fairing, and the at least one moving flap orienting itself automatically and passively.

Claims

1. A rotorcraft comprising: a rotor for providing at least lift for the rotorcraft in the air, the rotor being mounted to rotate about a first axis of rotation; an aerodynamic device arranged below the rotor, the aerodynamic device comprising a fairing provided with at least one air inlet for enabling a stream of cool air to flow from a region that is situated outside the rotorcraft to another region that is situated inside the rotorcraft; wherein at least at a mouth of the at least one air inlet in the fairing, the aerodynamic device comprises at least one moving flap that is mounted to move in rotation, the at least one moving flap having at least one degree of freedom of movement in rotation about a second axis of rotation relative to the fairing, the at least one moving flap orienting itself automatically and passively as a function of a current orientation of the stream of cool air at the mouth of the air inlet, and the second axis of rotation being arranged in a plane that extends perpendicularly relative to the first axis of rotation; wherein the at least one moving flap extends longitudinally between two facing faces that define the air inlet, a first end of the at least one moving flap comprising a first bearing arranged on a stationary pin passing through the at least one moving flap, and a second end of the at least one moving flap comprising a second bearing arranged on the stationary pin, the first and second bearings being arranged in alignment on the second axis of rotation.

2. The rotorcraft according to claim 1, wherein the at least one moving flap includes a first moving flap and a second moving flap, the first and second moving flaps being free to orient themselves individually to take up at least two angular orientations that are mutually distinct about respective ones of the second axes of rotation.

3. The rotorcraft according to claim 1, wherein the at least one moving flap includes a first moving flap and a second moving flap, the first and second moving flaps pivotable into the same angular orientation about respective ones of the second axes of rotation.

4. The rotorcraft according to claim 1, wherein the first bearing is arranged in a first face, and the second bearing is arranged in a second face.

5. The rotorcraft according to claim 1, wherein the at least one moving flap includes a first flap mounted to move in rotation about the second axis of rotation and a second flap mounted to move in rotation about a third axis of rotation, the second and third axes of rotation being arranged to be mutually parallel.

6. The rotorcraft according to claim 1, wherein the at least one moving flap includes a first flap mounted to move in rotation about a second axis of rotation, a second flap mounted to move in rotation about a third axis of rotation, and a third flap mounted to move in rotation about a fourth axis of rotation, the axes of rotation of the first, second, and third moving flaps being arranged in coplanar manner.

7. The rotorcraft according to claim 1, wherein the at least one moving flap has a plurality of cross-sections that are perpendicular to the second axis of rotation, each of the plurality of cross-sections having the same aerodynamic profile.

8. The rotorcraft according to claim 1, wherein the at least one moving flap has a plurality of cross-sections that are perpendicular to the second axis of rotation, the plurality of cross-sections having at least two mutually dissimilar profiles.

9. The rotorcraft according to claim 1, wherein the at least one moving flap includes a first moving flap and a second moving flap, the first and second moving flaps being mutually identical.

10. The rotorcraft according to claim 1, wherein the at least one moving flap includes a first moving flap and a second moving flap, the first and second moving flaps being dissimilar from each other.

11. The rotorcraft according to claim 1, wherein the at least one moving flap is of a streamlined type, the at least one moving flap having firstly a top skin and a bottom skin and secondly a leading edge interconnecting the top skin and the bottom skin and a trailing edge interconnecting the top skin and the bottom skin.

12. The rotorcraft according to claim 1, wherein the at least one moving flap has a plane shape extending substantially longitudinally along the second axis of rotation.

13. The rotorcraft according to claim 1, wherein, for each one of the at least one moving flap, the aerodynamic device comprises at least one abutment member suitable for angularly limiting the at least one degree of freedom of movement in rotation relative to the fairing.

14. The rotorcraft according to claim 1, wherein the at least one moving flap has a center of gravity, the center of gravity being arranged in such a manner so that the at least one moving flap is urged automatically back into a predetermined angular orientation when the flow-rate of the stream of cool air is zero, the predetermined angular orientation enabling the at least one moving flap to maximize closing-off of the mouth of the air inlet.

15. The rotorcraft according to claim 1, wherein, for each of the at least one moving flap, the aerodynamic device comprises at least one resilient means suitable for urging the at least one moving flap back into a predetermined angular position when the flow-rate of the stream of cool air is zero, the predetermined angular orientation enabling the at least one moving flap to maximize closing-off of the mouth of the air inlet.

16. The rotorcraft according to claim 1, wherein the at least one moving flap may have a varying angular orientation between a first orientation and a second orientation depending upon a current orientation of the stream of air at the mouth of the air inlet.

17. A rotorcraft comprising: a rotor mounted to rotate about a first axis of rotation to provide lift for the rotorcraft in the air; an aerodynamic device arranged below the rotor; the aerodynamic device comprising a fairing having an air inlet for enabling a stream of air to flow from outside the rotorcraft to inside the rotorcraft; wherein at a mouth of the air inlet in the fairing, the aerodynamic device comprises a moving flap mounted to move in rotation, the moving flap having at least one degree of freedom of movement in rotation about a second axis of rotation relative to the fairing, the moving flap orienting itself automatically and passively as a function of a current orientation of the stream of air at the mouth of the air inlet to enable the size of the cross-sectional area through which the stream of air passes at the mouth to be adapted automatically as a function of the flow-rate and of the orientation of the stream of air at the mouth of the air inlet, and the second axis of rotation arranged in a plane that extends perpendicularly relative to the first axis of rotation, wherein the moving flap may have a varying angular orientation between a first orientation and a second orientation depending upon a current orientation of the stream of air at the mouth of the air inlet; wherein the at least one moving flap extends longitudinally between two facing faces that define the air inlet, a first end of the at least one moving flap comprising a first bearing arranged on a stationary pin passing through the at least one moving flap, and a second end of the at least one moving flap comprising a second bearing arranged on the stationary pin, the first and second bearings being arranged in alignment on the second axis of rotation.

18. The rotorcraft according to claim 17, further comprising a second moving flap, wherein the moving flap and the second moving flap are free to orient themselves individually to take up at least two angular orientations that are mutually distinct about respective ones of the second axes of rotation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the following description of examples given by way of illustration with reference to the accompanying figures, in which:

(2) FIG. 1 is a perspective view of a rotorcraft of the invention;

(3) FIG. 2 is a front view of a first variant of the aerodynamic device of the invention;

(4) FIG. 3 is a front view of a second variant of the aerodynamic device of the invention;

(5) FIG. 4 is a cross-section view of a first embodiment of a moving flap of the invention;

(6) FIG. 5 is a perspective view of a second embodiment of a moving flap of the invention;

(7) FIG. 6 is a cross-section view showing a first angular orientation of the moving flaps of the invention;

(8) FIG. 7 is a cross-section view showing a second angular orientation of the moving flaps of the invention; and

(9) FIG. 8 is a cross-section view showing a third angular orientation of the moving flaps of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(10) Elements present in more than one of the figures may be given the same references in each of them.

(11) As indicated above, the invention relates to a rotorcraft having at least one rotor that at least participates in providing lift, and may also participate in providing propulsion, for the rotorcraft in the air.

(12) As shown in FIG. 1, such a rotorcraft 1 may have an aerodynamic device 2 arranged below the rotor 3.

(13) This rotor 3 rotates about a first a first axis of rotation OZ that, for example, extends substantially vertically while the rotorcraft 1 is standing on a horizontal support. Furthermore, the aerodynamic device 2 has a fairing 4 that is provided with at least one air inlet 5 making it possible for a stream of cool air to flow from a region situated outside the rotorcraft 1 to another region that is situated inside the rotorcraft 1.

(14) As shown, such an air inlet 5 may, for example, make it possible to feed cool air to a heat exchanger of the air-oil type designed to cool a lubricating oil of an engine or of a main gear box of the aircraft 1. Such members (not shown) may be arranged under the fairing 4.

(15) The air inlet 5 thus has a mouth 6 at which the aerodynamic device 2 has at least one moving flap V1, V2, V3 mounted to move in rotation. As shown, the three moving flaps V1, V2, and V3 respectively have at least one degree of freedom to move in rotation about a second axis of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2, O.sub.3Y.sub.3 relative to the fairing 4.

(16) Thus, the three moving flaps V1, V2, and V3 may orientate themselves automatically and passively as a function of a current orientation of the stream of cool air at the mouth 6 of the air inlet 5. Furthermore, the second axes of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2, O.sub.3Y.sub.3 are arranged in planes X.sub.1O.sub.1Y.sub.1, X.sub.2O.sub.2Y.sub.2, X.sub.3O.sub.3Y.sub.3 that are oriented perpendicularly relative to the first axis of rotation OZ.

(17) In addition, a first moving flap V1 and a second moving flap V2 may be free to orient themselves individually in at least two mutually distinct angular orientations about respective ones of the second axes of rotation O.sub.1Y.sub.1 and O.sub.2Y.sub.2.

(18) Alternatively, the first moving flap and the second moving flap may also pivot together into the same angular orientation about respective ones of the second axes of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2. In this situation, connecting rods (not shown) may, for example, make it possible to constrain the first and second moving flaps to move together.

(19) Furthermore, and as shown, the second axes of rotation O.sub.1Y.sub.1 and O.sub.2Y.sub.2 may be arranged to be mutually parallel at the mouth 6 of the air inlet 5.

(20) In addition, all three moving flaps V1, V2, and V3 may pivot about respective ones of second axes of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2, and O.sub.3Y.sub.3. These three second axes of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2, and O.sub.3Y.sub.3 may then advantageously be arranged in coplanar manner.

(21) In such an embodiment, the first and second moving flaps V1 and V2 may be chosen to be mutually identical.

(22) As shown in FIG. 2, in a first variant of the aerodynamic device 4, a moving flap V1 may extend longitudinally at the mouth 6 of the air inlet 5 between two faces 7 and 8 arranged facing each other.

(23) In this first variant, a first end 10 of the moving flap V1 then co-operates with a first bearing 11 arranged in a first face 7, and a second end 12 of the moving flap V1 co-operates with a second bearing 13 arranged in a second face 8. In addition, the first and second bearings 11 and 13 may then be arranged in alignment on the second axis of rotation O.sub.1Y.sub.1.

(24) As shown in FIG. 3, and in a second variant of the aerodynamic device 4, a moving flap V1′ may extend longitudinally at a mouth 26 between two facing faces 17 and 18 of an air inlet 25. In this situation, a first end 20 of the moving flap V1′ may co-operate with a first bearing 21 arranged on a stationary pin 24 that passes through the moving flap V1′, and a second end 22 of the moving flap V1′ may co-operate with a second bearing 23 arranged on the stationary pin 24.

(25) Similarly, the first and second bearings 21 and 23 may then be arranged in alignment on the second axis of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2, O.sub.3Y.sub.3.

(26) Furthermore, and as shown, the first and second moving flaps V1′ and V2′ may be distinct from each other and have different lengths along their respective second axes of rotation O.sub.1Y.sub.1 and O.sub.2Y.sub.2.

(27) As shown in FIG. 4, and in a first embodiment, a moving flap V1 may have a plurality cross-sections that are perpendicular to the second axis of rotation O.sub.1Y.sub.1, each of which has the same aerodynamic profile P1.

(28) Furthermore, the moving flap V1 may be of a streamlined type. Thus, the moving flap V1 has firstly a top skin 30 and a bottom skin 31, and secondly a leading edge 32 interconnecting the top skin 30 and the bottom skin 31, and a trailing edge 33 interconnecting the top skin 30 and the bottom skin 31. Such a leading edge 32 and such a trailing edge 33 may then extend substantially longitudinally along the second axis of rotation O.sub.1Y.sub.1.

(29) Furthermore, in the plane of FIG. 4, corresponding to the plane X.sub.1O.sub.1Z.sub.1, the mouth 6 points towards a front region of the rotorcraft and is inclined upwards at an angle α relative to an axis in elevation O.sub.1Z.sub.1. Such an angle α may lie in the range 1° to 89°, and preferably lies in the range 20° to 60°, in such a manner as to cause a cross-sectional area through which cool air can pass at the mouth 6 to vary as a function of the angle of incidence of the stream of cool air at the mouth 6.

(30) In addition, the aerodynamic device 2 may have at least one abutment member 40 suitable for angularly limiting the degree of freedom of movement in rotation of the moving flap V1 relative to the fairing 4.

(31) Moreover, such a moving flap V1 has a center of gravity G that may be arranged in such a manner as to be radially offset relative to the second axis of rotation O.sub.1Y.sub.1 and, for example, positioned between the leading edge 32 and the second axis of rotation O.sub.1Y.sub.1. In this way, the Earth's gravitational force applied to the moving flap V1 makes it possible to urge the moving flap V1 automatically back into a predetermined angular orientation when the flow rate of the stream of cool air is zero.

(32) Advantageously, such a predetermined angular orientation enables the moving flap V1 to maximize closing-off of the mouth 6 of the air inlet 5.

(33) As shown in FIG. 5, and in a second embodiment, a moving flap V1′ may have a plurality cross-sections that are perpendicular to the second axis of rotation O.sub.1Y.sub.1. Such a plurality of cross sections may then have at least two mutually distinct profiles P1′ and P2′.

(34) In this second embodiment, the moving flap V1′ may also have a plane shape extending substantially longitudinally along the second axis of rotation O.sub.1Y.sub.1.

(35) Additionally or alternatively, the aerodynamic device 4 may also have at least one resilient return means 41 making it possible to urge the moving flap V1′ back into a predetermined angular orientation when the flow rate of the stream of cool air is zero.

(36) Such a predetermined angular orientation may enable the moving flap V1′ to maximize closing-off of the mouth 26 of the air inlet 25.

(37) Furthermore, and as shown in FIGS. 6 to 8, the moving flaps V1, V2, and V3 are suitable for pivoting freely about their respective second axes of rotation O.sub.1Y.sub.1, O.sub.2Y.sub.2, and O.sub.3Y.sub.1 between at least three distinct angular orientations as a function of the angle of incidence of the stream of cool air at the mouth 6. Such a mouth 6 is also, as shown, significantly inclined upwards at an angle α relative to an axis in elevation O.sub.1Z.sub.1.

(38) Thus, as shown in FIG. 6, when the moving flaps V1, V2, and V3 of the streamlined type are in a first angular orientation, and when the stream of cool air is mainly oriented in the direction extending downwards from top to bottom of the rotorcraft 1, the leading edge 32 of each moving flap V1, V2, and V3 is then arranged in a horizontal plane that is situated above another horizontal plane containing the trailing edge 33, and that extends perpendicularly relative to the first axis of rotation OZ, the two horizontal planes extending on either side of the respective one of the planes X.sub.1O.sub.1Y.sub.1, X.sub.2O.sub.2Y.sub.2, and X.sub.3O.sub.3Y.sub.3.

(39) As shown in FIG. 7, in a second angular orientation, when the stream of cool air is mainly oriented in the direction extending from the front to the rear of the rotorcraft 1, the leading edges 32 and the trailing edges 33 of the moving flaps V1, V2, and V3 are then arranged in respective ones of the planes X.sub.1O.sub.1Y.sub.1, X.sub.2O.sub.2Y.sub.2, and X.sub.3O.sub.3Y.sub.3.

(40) As shown in FIG. 8, in a third angular orientation, when the flow-rate of the stream of cool air is zero, the leading edge 32 of each moving flap V1, V2, and V3 is then arranged in a horizontal plane situated below another horizontal plane containing the trailing edge 33, the two horizontal planes extending on either side of the respective one of the planes X.sub.1O.sub.1Y.sub.1, X.sub.2O.sub.2Y.sub.2, and X.sub.3O.sub.3Y.sub.3.

(41) Naturally, the present invention can be the subject of numerous variants as to its implementation. Although several embodiments are described, it should readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.