AERODYNAMICS INFLUENCING DEVICE FOR AN AIRCRAFT AND AIRCRAFT

Abstract

An aerodynamic device (1, 11), such as for an aircraft, including a frame (2), a skin (6) forming an aerodynamic surface and connected to the frame (2) and a motile portion (4) adapted to be displaced between a first position in which the aerodynamic surface exhibits a first shape, and a second position different from the first position, wherein the mobile portion includes a disturbing structure (3), and in the second position of the motile portion (4), and the aerodynamic surface exhibits a second shape in which the disturbing structure (3) induces a protrusion (14) on the aerodynamic surface.

Claims

1. An aerodynamic device comprising: a frame, a skin: having an outer surface forming at least part of an aerodynamic surface, at least partially connected to the frame, and comprising a motile portion adapted to be displaced between: a first position in relation to the frame, in which the aerodynamic surface forms a first shape, and a second position in relation to the frame, the second position being different from the first position, and a disturbing structure, wherein, while the motile portion is in the second position, the aerodynamic surface forms a second shape, different from the first shape, in which the disturbing structure induces a protrusion of or from the aerodynamic surface.

2. The aerodynamic device according to claim 1, wherein the disturbing structure is fixed in relation to the frame.

3. The aerodynamic device according to claim 1, wherein the disturbing structure is fixed in relation to the motile portion.

4. The aerodynamic device according to claim 1, wherein the skin includes a deformable skin.

5. The aerodynamic device according to claim 1, wherein the skin is entirely deformable.

6. The aerodynamic device according to claim 4, wherein: in the first position of the motile portion, the deformable skin has a first shape, and in the second position of the motile portion, the deformable skin is at least partially restrained by the disturbing structure such that the deformable skin has a second shape different from the first shape.

7. The aerodynamic device according to claim 4, wherein the disturbing structure is at least partially attached to the deformable skin, and is adapted to modify locally a deformability of the deformable skin.

8. The aerodynamic device according to claim 4, wherein, while the motile portion is in the first position, the disturbing structure at least partially supports the deformable skin while the deformable skin is in the first shape.

9. The aerodynamic device according to claim 4, wherein the deformable skin comprises a slit and, while the motile portion is in the second position, the disturbing structure restrains a first side of the slit differently that a restraint applied by the disturbing structure to a second side of the slit.

10. The aerodynamic device according to claim 4, wherein: the skin comprises an aperture, while the motile portion is the first position, the skin and a surface of the disturbing structure form a continuous aerodynamic surface, and while the mobile portion is in the second position, the skin and the surface of the disturbing structure form a discontinuous aerodynamic surface.

11. The aerodynamic device according to claim 1, wherein, while the motile portion is in the second position, the disturbing structure protrudes from the skin.

12. The aerodynamic device according to claim 1, wherein the motile portion forms at least part of a trailing edge portion of a wing.

13. The aerodynamic device according to claim 1, wherein the disturbing structure is a plurality of disturbing structures.

14. A wing for an aircraft comprising the aerodynamic device according to claim 1.

15. An aircraft comprising the aerodynamic device according to claim 1.

Description

SUMMARY OF THE DRAWINGS

[0093] Some specific exemplary embodiments and aspects of the invention are described in the following description in reference to the accompanying figures.

[0094] FIG. 1A is a schematic representation of a transversal cross-section of a wing comprising an embodiment of a device according to the invention in a first configuration,

[0095] FIG. 1B is a schematic representation of a longitudinal cross-section IB-IB of a wing according to the embodiment of FIG. 1A,

[0096] FIG. 2 is a schematic representation of a transversal cross-section of the device of FIG. 1A in a second configuration,

[0097] FIG. 3A is a schematic representation of a transversal cross-section of the device of the FIGS. 1 and 2 in a third configuration,

[0098] FIG. 3B is a schematic representation of a longitudinal cross-section IIIB-IIIB of a wing according to the embodiment of FIG. 3A,

[0099] FIG. 4 is a schematic side representation of a vertical tail plane of an aircraft comprising an embodiment of a device according to the invention, with a broken-out section.

[0100] FIG. 5 is a schematic representation of a transversal cross-section V-V of the device of FIG. 4 in a first configuration,

[0101] FIG. 6 is a schematic representation of a transversal cross-section V-V of the device of FIG. 4 in a second configuration,

[0102] FIG. 7 is a schematic representation of a transversal cross-section of a wing comprising an embodiment of a device according to the invention in a first configuration,

[0103] FIG. 8 is a schematic representation of a transversal cross-section of the device of FIG. 7 in a second configuration,

[0104] FIG. 9 is a schematic representation of a transversal cross-section of a wing comprising an embodiment of a device according to the invention in a first configuration,

[0105] FIG. 10 is a schematic representation of a longitudinal cross-section X-X of the device of FIG. 9,

[0106] FIG. 11 is a schematic representation of a transversal cross-section of the device of FIG. 9 in a second configuration,

[0107] FIG. 12 is a schematic representation of a longitudinal cross-section XII-XII of the device of FIG. 11,

[0108] FIG. 13 is a schematic representation of a transversal cross-section of a wing comprising an embodiment of a device according to the invention in a first configuration,

[0109] FIG. 14 is a schematic representation of a longitudinal cross-section XIV-XIV of the device of FIG. 13,

[0110] FIG. 15 is a schematic representation of a transversal cross-section of the device of FIG. 13 in a second configuration,

[0111] FIG. 16 is a schematic representation of a longitudinal cross-section XVI-XVI of the device of FIG. 15,

[0112] FIG. 17 is a schematic representation of a transversal cross-section of a vertical tail plane of an aircraft comprising an embodiment of a device according to the invention, in a first configuration,

[0113] FIG. 18 is a schematic representation corresponding to the embodiment shown in FIG. 17, in a second configuration,

[0114] FIG. 19 is a schematic representation of a transversal cross-section of a vertical tail plane of an aircraft comprising an embodiment of a device according to the invention, in a first configuration,

[0115] FIG. 20 is a schematic representation corresponding to the embodiment shown in FIG. 19, in a second configuration.

DETAILED DESCRIPTION

[0116] In FIGS. 1A and 1B a wing 1 is represented in a first configuration corresponding to a cruise speed of a plane. In such configuration, the wing 1 has a limited curvature adapted to provide lift with a minimum drag. The air flow flowing along the intrados 8 is not deflected.

[0117] The chord axis X and the thickness axis Z are represented as referential between each of the three configurations represented in FIGS. 1A, 2 and 3A.

[0118] The wing 1 comprises a frame 2 comprising for example a rib. A skin 6 is attached to the frame 2 so as to cover it and form an aerodynamic surface. The wing comprises a leading edge 10 and a trailing edge 9 between which extend an extrados 7, such as an upper wing skin surface, and an intrados 8, such as a lower wing skin surface.

[0119] The trailing portion of the wing comprises a motile portion 4 in the form of a morphing portion of the wing. The motile portion is a movable portion of the wing and may for example be a flap. In this embodiment, the skin 6 may be semi-rigid. The skin of the motile portion 4 of the wing 1 may be actuated by different techniques such as local actuators or actuated elements articulated with the frame such as for example an actuated trailing portion of a rib. The trailing portion of the wing may also comprise elements comprising memory shape materials so that their shape may change under a given stimulus such as for example a given temperature reached by heating.

[0120] The frame 2 comprises a disturbing structure 3 integral with the rest of the frame.

[0121] In the embodiment represented in FIGS. 1A and 1B the skin 6 comprises an aperture 5 which is filled by the disturbing structure 3. The disturbing structure 3 has an outer surface which forms a continuous aerodynamic surface with the skin 6. Therefore in this first configuration, the aerodynamic surface of the wing, in particular the surface of the extrados 8 is continuous, smooth and doesn't present high local variations of curvature. It is adapted for example to a flow of air at an aircraft cruise speed and with a small angle of attack.

[0122] In FIG. 2, the motile portion 4 of the wing 1 has been actuated so that the wing is placed in a second configuration which presents a transversal cross-section with a higher curvature in relation to the first configuration. The motile portion 4 representing a trailing portion of the wing is adapted to deflect an air flow flowing from the leading edge 10 towards the trailing edge 9 with a first deflecting angle 16. In this second configuration a higher lift is obtained in relation to the first configuration, due to the higher deflections of air flow on the extrados 7 and on the intrados 8.

[0123] In this second configuration, the disturbing structure 3 protrudes from the skin's outer surface. The global aerodynamic surface of the wing therefore comprises a local discontinuity where the disturbing structure 3 protrudes from the wing.

[0124] The invention presents the benefit that the disturbing structure 3 requires no actuation. Thereby the outer shape of the aerodynamic surface is modified between a first position of the motile portion and a second position of the motile portion, without additional motile portion than the motile portion itself. The aerodynamic surface of a device according to the invention, and of an aircraft may thus be locally modified depending on the global shape adopted by said aerodynamic surface. Moreover the local shape of the aerodynamic surface directly depends on the global shape of the aerodynamic surface.

[0125] In relation to this embodiment, it may be noted that the disturbing structure 3 may have different shapes. It may for example have a cylindrical section, a cuboid section, or another section. Although in the embodiment represented on FIG. 3B, the disturbing structure 3 is local, the disturbing structure 3 may also be linear so that it extends along at least a portion of the wing span, thus forming a rib on the extrados 8 of the wing 1 when it protrudes from it. The local protrusion (or bump) formed at the discontinuity between the surface of the disturbing structure 3 and the skin 6 may allow the formation of local vortices in an air flow flowing from the leading edge 10 towards the trailing edge 9, more particularly from the disturbing structure 3 towards the trailing edge 9. These vortices permit the boundary layer of the air flow to stay along the surface of the wing even at high angles of attack so that the air flow does not separate and/or stall.

[0126] In the third configuration of the FIGS. 3A and 3B, the deflection of the motile portion 4 is amplified compared to the second configuration. The first position of the motile skin 4 is represented on FIGS. 2 and 3A in dotted lines for comparison with the second and third positions of FIGS. 2 and 3A respectively.

[0127] As represented on FIGS. 3A and 3B, in this third configuration of the motile portion 4, the disturbing structure 3 emerges from an aperture 5 in the skin 6 of the wing 1.

[0128] In the third configuration, the trailing portion of the wing forms a deflection angle 17 bigger than the angle 16, such that the disturbing structure 3 protrudes more from the skin 6. This configuration may correspond for example to the configuration of an airplane wing at landing, providing a high deflection of air flow to provide the airplane with a high lift at low speed.

[0129] On FIGS. 4, 5 and 6, a vertical tail plane 11 according to the invention is represented. The vertical tail plane comprises a fore portion 12 or vertical stabilizer, which is fixed in relation to a frame of the plane and to the fuselage. In fact the fore portion of the vertical tail plane comprises a frame 2 and a skin covering the frame to form an aerodynamic surface with a leading edge 10.

[0130] The vertical tail plane comprises a trailing edge portion comprising a rudder. The rudder is the motile portion 4 of the vertical tail plane. The rudder 4 comprises a trailing edge 9. The rudder is motile and actuated around a rotation axis 15.

[0131] The rudder comprises a skin 6. The skin 6 comprises at least a flexible, elastic portion, called the deformable skin 13.

[0132] Moreover the frame 2 comprises a disturbing structure 3 which is integral with the frame 2. The disturbing structure 3 extends into the rudder 4. The disturbing structure 3 presents an anvil shape with an extremity which is wider than its basis.

[0133] In the first configuration represented on FIG. 5, the rudder 4 is in a neutral position whereby, when placed in an air flow, it does not deflect the air flow towards one side or another. In this first configuration, the disturbing structure 3 is not solicited and does not influence the shape of the skin 6.

[0134] In the second configuration represented on FIG. 6 corresponding to a second position of the rudder 4. The rudder is rotated around the rotation axis 15 so that it may deflect an air flow flowing around the vertical tail plane 11. Thus in relation to the air flow, it may be considered that an extrados 7 and an intrados 8 are formed respectively on each side of the rudder 4.

[0135] In this second configuration, the extrados 7 of the skin 6 has been brought against the disturbing structure 3 by the rotation of the rudder 4. As the skin 6 comprises in this area a deformable skin 13, the deformable skin 13 adopts partially the shape of the disturbing structure 3. Thereby the deformable skin forms a local protrusion, or bump 14, on the extrados 7. Such bump may provoke the formation of a local vortex in an air flow flowing around the vertical tail plane from its leading edge 10 to its trailing edge 9 on the rudder 4. As above described, the local vortex may help the boundary layer of air to remain along the aerodynamic surface of the rudderthereby avoiding stallup until higher angles of deflection than with a generally smooth extrados 7.

[0136] Similarly, when the rudder 4 is actuated to the opposite side, the deformable skin 13 of the opposite side of the rudder 4 will be restrained to form a local bump on the skin 6 of the rudder.

[0137] In FIG. 7, another embodiment of the invention is represented. A wing 1 is represented in a first configuration corresponding for example to a cruise speed of a plane. In such configuration, the wing 1 has a limited curvature adapted to provide lift with a minimum drag. The air flow flowing along the intrados 8 is not deflected.

[0138] The wing 1 comprises a frame 2 comprising for example a rib. A skin 6 is attached to the frame 2 so as to cover it and form an aerodynamic surface. The wing comprises a leading edge 10 and a trailing edge 9 between which extend an extrados 7 and an intrados 8.

[0139] The trailing portion of the wing comprises a motile portion 4. The motile portion may for example be a rigid or semi-rigid flap. In this embodiment, the skin 6 may be rigid.

[0140] The motile portion 4 may be actuated by different techniques such as local actuators or actuated elements articulated with the frame such as for example an actuated trailing portion of a rib. The trailing portion of the wing may also comprise elements comprising memory shape materials so that their shape may change under a given stimulus such as for example a given temperature reached by heating. In this embodiment, the motile portion is articulated compared to the frame 2 in rotation around a rotation axis 18.

[0141] The motile portion 4 comprises a disturbing structure 3 which is motile compared to the frame 2. In particular the disturbing structure 3 may be integral with the motile portion 4 such that it is displaced with the motile portion 4. The invention presents the benefit that the disturbing structure 3 requires no dedicated actuation.

[0142] The disturbing structure 3 is arranged on a front portion of the motile portion 4, in particular in front of a rotation axis 18 of the motile portion 4, such that the disturbing structure is within the aerodynamic envelope of the wing in a first configuration such as represented on FIG. 7, but emerges locally from the aerodynamic envelope of the wing in a second configuration such as represented in FIG. 8.

[0143] In the embodiment represented in FIG. 7 the skin 6 comprises an aperture 5 which is filled by the disturbing structure 3. The disturbing structure 3 has an outer surface which forms a continuous aerodynamic surface with the skin 6. Therefore in this first configuration, the aerodynamic surface of the wing, in particular the surface of the extrados 8 is continuous, smooth and doesn't present high local variations of curvature. It is adapted for example to a flow of air at an aircraft cruise speed and with a small angle of attack.

[0144] In FIG. 8, the motile portion 4 of the wing 1 has been actuated so that the wing is placed in a second configuration which presents a transversal cross-section with a higher curvature in relation to the first configuration. The motile portion 4 representing a trailing portion of the wing is adapted to deflect an air flow flowing from the leading edge 10 towards the trailing edge 9. In this second configuration a higher lift is obtained in relation to the first configuration, due to the higher deflections of air flow on the extrados 7 and on the intrados 8.

[0145] In this second configuration, the disturbing structure 3 protrudes from the skin's outer surface. The global aerodynamic surface of the wing therefore comprises a local discontinuity where the disturbing structure 3 protrudes.

[0146] The height of the protrusion depends on the relative position of the motile portion 4 and of the frame 2. The more the motile portion is displaced towards increasing the curvature of the wing, the more the disturbing structure 3 protrudes.

[0147] Again in this embodiment, the disturbing structure 3 may have different shapes and may be local or linear so that it extends along at least a portion of the wing span, thus forming a rib on the wing 1 when it protrudes from it. The local protrusion (or bump) formed at the discontinuity between the surface of the disturbing structure 3 and the skin 6 may allow for the formation of local vortices in an air flow flowing from the leading edge 10 towards the trailing edge 9. These vortices permit the boundary layer of the air flow to stay along the surface of the wing even at high angles of attack so that the air flow does not separate and/or stall.

[0148] In FIGS. 9 and 10, another embodiment of the invention is represented. A wing 1 is represented in a first configuration corresponding for example to a cruise speed of a plane. In such configuration, the wing 1 has a limited curvature adapted to provide lift with a minimum drag. The air flow flowing along the intrados 8 is not deflected.

[0149] The wing 1 comprises a frame 2 comprising for example a rib. A skin 6 is attached to the frame 2 so as to cover it and form an aerodynamic surface. The wing comprises a leading edge 10 and a trailing edge 9 between which extend an extrados 7 and an intrados 8.

[0150] The front portion of the wing is in this embodiment fixed compared to the frame, and in particular the skin 6 of the front portion of the wing 1 is in this embodiment attached fixedly to the frame 2. However, in other embodiments according to the invention, the skin 6 of the fore portion of a wing or of another aerodynamic device may not be fixed to the frame 2.

[0151] The trailing portion of the wing comprises a motile portion 4 which also comprises a skin 6. The motile portion may for example be a rigid or semi-rigid flap. In this embodiment, the skin 6 may be rigid and comprise a deformable portion 13 at least at a junction between the motile portion 4 and a front portion of the wing.

[0152] The motile portion 4 may be actuated by different techniques such as local actuators or actuated elements articulated with the frame such as for example an actuated trailing portion of a rib. The trailing portion of the wing may also comprise elements comprising memory shape materials so that their shape may change under a given stimulus such as for example a given temperature reached by heating. In this embodiment, the motile portion is articulated compared to the frame 2 in rotation around a rotation axis 18.

[0153] The wing 1 comprises a disturbing structure 3 which is fixed in relationship to the frame 2. In particular the disturbing structure 3 may be integral with the frame 2. The invention presents the benefit that the disturbing structure 3 requires no dedicated actuation.

[0154] The disturbing structure 3 is arranged in an aft portion of the frame 2, in particular behind a rotation axis 18 of the motile portion 4, such that the disturbing structure 3 is within the aerodynamic envelope of the wing 1 in a first configuration such as represented on FIG. 9 and FIG. 10, but emerges locally from the aerodynamic envelope of the wing 1 in a second configuration such as represented in FIGS. 11 and 12.

[0155] In the embodiment represented in FIGS. 9 to 12 the skin 6 comprises a deformable portion, called deformable skin 13. The deformable skin 13 may beneficially be elastic. The deformable skin 13 is arranged on the motile portion 4 in the vicinity of the disturbing structure 3.

[0156] The deformable skin 13 is supported by the disturbing structure 3 in a first configuration represented by FIGS. 9 and 10. This minimizes the deformation of the deformable skin 13 under the influence of external elements such as air turbulences. To improve this aspect, the deformable skin 13 may at least partially be attached to the disturbing structure 3 such that the disturbing structure 3 not only supports the deformable skin in a first direction, but also retains the deformable skin in a second direction opposite the first direction.

[0157] In the first configuration, the wing thus has an outer surface which forms a continuous aerodynamic surface, in which the deformable skin 13 is smooth with the rest of the skin 6 of the wing and has a low degree of curvature locally, except for the leading edge 10 and the trailing edge 9. Therefore in this first configuration, the aerodynamic surface of the wing, in particular the surface of the extrados 8 is continuous, smooth and does not present high local variations of curvature. It is adapted for example to a flow of air at an aircraft cruise speed and with a small angle of attack.

[0158] In FIGS. 11 and 12, the motile portion 4 of the wing 1 has been actuated so that the wing is placed in a second configuration which presents a transversal cross-section with a higher curvature in relation to the first configuration. The motile portion 4 representing a trailing portion of the wing is adapted to deflect an air flow flowing from the leading edge 10 towards the trailing edge 9. In this second configuration a higher lift is obtained in relation to the first configuration, due to the higher deflections of air flow on the extrados 7 and on the intrados 8.

[0159] In this second configuration, the disturbing structure 3, being fixed to the frame, induces a deformation of the deformable skin 13 of the motile portion as the motile portion is actuated around the axis 18, such that the disturbing structure 3 and the deformable skin 13 protrude locally to form a bump 14 with a high local curvature variation of the aerodynamic surface. The aerodynamic surface of the wing therefore comprises a high local curvature variation where the disturbing structure 3 induces the deformable skin 13 to protrude.

[0160] The height of the protrusion depends on the relative position of the motile portion 4 and of the frame 2. The more the motile portion is displaced towards increasing the curvature of the wing, the more the disturbing structure 3 protrudes.

[0161] In this embodiment, the disturbing structure represented is local in the spanwise direction, however, the disturbing structure 3 may have different shapes and may be local or linear so that it extends along at least a portion of the wing span, thus forming a rib on the wing 1 when it protrudes from it. The local protrusion (or bump) formed on the surface of the skin 6 may allow for the formation of local vortices in an air flow flowing from the leading edge 10 towards the trailing edge 9. These vortices permit the boundary layer of the air flow to stay along the surface of the wing even at high angles of attack so that the air flow does not separate and/or stall.

[0162] In FIGS. 13 and 15, yet another embodiment of the invention is represented. A wing 1 is represented in a first configuration corresponding for example to a cruise speed of a plane. In such configuration, the wing 1 has a limited curvature adapted to provide lift with a minimum drag. The air flow flowing along the intrados 8 is not deflected.

[0163] The wing 1 comprises a frame (not represented) comprising for example a rib. A skin 6 is attached to the frame 2 so as to cover it and form an aerodynamic surface, but in this embodiment, the skin 6 may deform such that the wing may be a morphing wing. In particular the skin 6 may be a deformable skin 13 such as a flexible and/or elastic skin. The skin 6 may be actuated by different techniques such as local actuators or actuated elements articulated with the frame. The wing may also comprise elements comprising memory shape materials so that their shape may change under a given stimulus such as for example a given temperature reached by heating. The skin itself may comprise memory shape material.

[0164] In this embodiment, the motile portion 4 may be considered to be the entire skin 6, the skin 6 being articulated compared to the frame.

[0165] The wing comprises a leading edge 10 and a trailing edge 9 between which extend an extrados 7 and an intrados 8.

[0166] The wing 1 comprises a disturbing structure 3 which is fixed to the skin 6. The disturbing structure 3 may be a stiffener which reduces locally the deformability, in particular the flexibility and/or the elasticity of the skin 6. The invention presents the benefit that the disturbing structure 3 requires no dedicated actuation.

[0167] In this embodiment, the disturbing structure 3 is arranged along the extrados of the wing, on an inner face of the skin 6.

[0168] The disturbing structure 3, by stiffening locally the skin 6, may minimize the deformation of the deformable skin 6 under the influence of external elements such as air turbulences.

[0169] In a first configuration represented, the wing thus has an outer surface which forms a continuous aerodynamic surface, in which the deformable skin 13 is smooth with the rest of the skin 6 of the wing and has a low degree of curvature locally, except for the leading edge 10 and the trailing edge 9. Therefore in this first configuration, the aerodynamic surface of the wing, in particular the surface of the extrados 8 is continuous, smooth and does not present high local variations of curvature. It is adapted for example to a flow of air at an aircraft cruise speed and with a small angle of attack.

[0170] In FIGS. 15 and 16, the wing 1 has been actuatedin particular the skin 6 of the wing has been deformedso that the wing is in a second configuration which presents a transversal cross-section with a higher curvature in relation to the first configuration. The trailing portion of the wing is adapted to deflect an air flow flowing from the leading edge 10 towards the trailing edge 9. In this second configuration a higher lift is obtained in relation to the first configuration, due to the higher deflections of air flow on the extrados 7 and on the intrados 8.

[0171] In this second configuration, the disturbing structure 3, being fixed to the skin 6, induces a deformation of the deformable skin as the skin is morphed towards the second configuration, such that the skin 13 comprises a local protrusion 14 forming a high local curvature variation of the aerodynamic surface. The aerodynamic surface of the wing therefore comprises a high local curvature variation where the disturbing structure 3 induces the deformable skin 13 to protrude. In this embodiment, the disturbing structure is represented as an elongated element extending along the chord, such that the protrusion 14 may have the form of a rib extending in the chord direction. The aft end of the disturbing structure also induces a high local variation of curvature such that the air flowing along the extrados may be influenced so as to form a vortex.

[0172] The height of the protrusion may depends on the difference of deformability between the skin 6 and the disturbing structure. In particular the height and shape of the protrusion 14 may depend on the stiffening induced by the disturbing structure on the skin 6.

[0173] In this embodiment, the disturbing structure represented is elongated in the chordwise direction, however, the disturbing structure 3 may have different shapes and may be local or linear so that it extends along at least a portion of the wing span, thus forming a rib on the wing 1. The local protrusion (or bump) formed on the surface of the skin 6 may allow for the formation of local vortices in an air flow flowing from the leading edge 10 towards the trailing edge 9. These vortices permit the boundary layer of the air flow to stay along the surface of the wing even at high angles of attack so that the air flow does not separate and/or stall.

[0174] On FIGS. 17 and 18 a vertical tail plane 11 according to the invention is represented. The vertical tail plane comprises a fore portion 12 which is fixed in relation to a frame of the plane and to the fuselage. In fact the fore portion of the vertical tail plane comprises a frame 2 and a skin covering the frame to form an aerodynamic surface with a leading edge 10.

[0175] The vertical tail plane comprises a trailing edge portion comprising a rudder. The rudder is the motile portion 4 of the vertical tail plane. The rudder 4 comprises a trailing edge 9. The rudder is motile and actuated around a rotation axis 15.

[0176] The rudder comprises a skin 6.

[0177] In this embodiment, the rudder 4 comprises at least two disturbing structures 3, respectively on each side of the rudder, and therefore on each side of the vertical tail plane 11.

[0178] The disturbing structures 3 may be placed symmetrically on each side of the rudder 4.

[0179] The disturbing structures 3 are placed towards the fore front of the rudder 4. The disturbing structures 3 are configured such that:

[0180] in the first configuration represented on FIG. 17, the two disturbing structures 3 are within the envelope of the vertical tail plane 11, and in particular within the envelope of the skin 6 of the fore portion 12,

[0181] in the second configuration, in which the rudder 4 is rotated around an axis 15 so as to deflect an airflow along the vertical tail place 11, as represented on FIG. 18, one of the disturbing structure 3 extends beyond the envelope of the vertical tail plane 11, and in particular beyond the envelope of the skin 6 of the fore portion 12, such that it forms a bump 14 on the aerodynamic surface, and in particular on a streamline of airflow along the skin 6 of the vertical tail plane. Vortices may thus be created in the streamline of air. Such bump 14 may provoke the formation of a local vortex in an air flow flowing around the vertical tail plane from its leading edge 10 to its trailing edge 9 on the rudder 4. As above described, the local vortex may help the boundary layer of air to remain along the aerodynamic surface of the rudderthereby avoiding stallup until higher angles of deflection than with a generally smooth extrados 7.

[0182] In this embodiment, the disturbing structures 3 are placed in front of the rotation axis 15 so as to emerge as a bump 14 from the aerodynamic envelope of the vertical tail plane 11 when the rudder is rotated.

[0183] The disturbing structures 3 may be configured such that they only emerge from the aerodynamic envelope for angles of the rudder higher than a predetermined angle.

[0184] The disturbing structures 3 may emerge from the aerodynamic surface through an opening in the skin 6 of the fore portion 12 of the vertical tail plane 11, or the skin 6 of the fore portion 12 may be locally deformable such that under the effect of the disturbing structure, the deformable skin is deformed so as to form a bump on the aerodynamic surface.

[0185] The disturbing structures 3 may be punctual along the length of the rudder, or may form a rib along the rudder 4.

[0186] There may be one or more disturbing structure 3 on each side of the rudder 4. A plurality of disturbing structures may be arranged spanwise and/or chordwise.

[0187] On FIGS. 19 and 20 a vertical tail plane 11 according to the invention is represented. The vertical tail plane comprises a fore portion 12 which is fixed in relation to a frame of the plane and to the fuselage. In fact the fore portion of the vertical tail plane comprises a frame 2 and a skin covering the frame to form an aerodynamic surface with a leading edge 10.

[0188] The vertical tail plane comprises a trailing edge portion comprising a rudder. The rudder is the motile portion 4 of the vertical tail plane. The rudder 4 comprises a trailing edge 9. The rudder is motile and actuated around a rotation axis 15.

[0189] The rudder comprises a skin 6.

[0190] In this embodiment, the fore portion 12 comprises at least two disturbing structures 3, respectively on each side of the rudder, and therefore on each side of the vertical tail plane 11.

[0191] The disturbing structures 3 may be placed symmetrically on each side of the fore portion 12.

[0192] The disturbing structures 3 are placed towards the aft of the fore portion 12. The disturbing structures 3 are configured such that:

[0193] in the first configuration represented on FIG. 19, the two disturbing structures 3 are within the envelope of the vertical tail plane 11, and in particular within the envelope of the skin 6 of the rudder 4,

[0194] in the second configuration, in which the rudder 4 is rotated around an axis 15 so as to deflect an airflow along the vertical tail place 11, as represented on FIG. 18, one of the disturbing structure 3 extends beyond the envelope of the vertical tail plane 11, and in particular beyond the envelope of the skin 6 of the rudder 4, such that it forms a bump 14 on the aerodynamic surface, and in particular on a streamline of airflow along the skin 6 of the vertical tail plane. Vortices may thus be created in the streamline of air. Such bump 14 may provoke the formation of a local vortex in an air flow flowing around the vertical tail plane from its leading edge 10 to its trailing edge 9. As above described, the local vortex may help the boundary layer of air to remain along the aerodynamic surface of the rudderthereby avoiding stallup until higher angles of deflection than with a generally smooth extrados 7.

[0195] In this embodiment, the disturbing structures 3 are arranged as aft extensions of the fore portion 12 towards the rudder 4, such that when the rudder is rotated the aerodynamic envelope has a bump 14 (which can also be seen a recess in this embodiment). To do so, the disturbing structures 3 are placed behind the rotation axis 15 towards the trailing edge 9, so as to emerge as a bump 14 from the aerodynamic envelope of the vertical tail plane 11 when the rudder is rotated.

[0196] The disturbing structures 3 may emerge from the aerodynamic surface through an opening in the skin 6 of the rudder 4 of the vertical tail plane 11, or the skin 6 of the rudder 4 may be locally deformable such that under the effect of the disturbing structure, the deformable skin is deformed so as to form a bump on the aerodynamic surface.

[0197] The disturbing structures 3 may be punctual along the length of the fore portion, or may form a rib along the fore portion 12.

[0198] There may be one or more disturbing structure 3 on each side of the fore portion 12. A plurality of disturbing structures may be arranged spanwise and/or chordwise.

[0199] The invention is not limited to the specific embodiments herein disclosed as examples. The invention also encompasses other embodiments not herein explicitly described, which may comprise various combinations of the features herein described.

[0200] Also the invention may be applied to devices in other fluids such as water for example. The invention may be adapted to a hydrodynamic device.

[0201] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.