Lift-generating device having axial fan(s), and heavier-than-air aircraft fitted with such a device

Patent metadata

Field	Value
Publication number	US-9694907-B2
Application number	US-201414904597-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 12, 2013
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

The invention relates to a device which includes two longitudinal deflecting surfaces or two pluralities of longitudinal deflecting surfaces, which are symmetrical on either side of the plane formed by the roll and yaw axes of the device and substantially in line with the roll axis and parallel to same, an air flow generator including at least one axial fan suctioning ambient air by means of at least one propeller faired in a flow path and, downstream of said propeller, an air distributor-diffuser, consisting of two adjacent semi-distributors each defining a curved duct directing the air to an outlet opening and toward the longitudinal deflecting surface or plurality of longitudinal deflecting surfaces.

First claim

The invention claimed is:

1. A lift-generating device for a vertical- or short-takeoff heavier-than-air aircraft, using the lift-generating effect obtained by blowing a majority of an air flow produced by an air flow generator over deflecting surfaces linked to a load-bearing structure, the device comprising two longitudinal deflecting surfaces, arranged on either side of a roll axis of the device and extending substantially parallel with said roll axis, said two longitudinal deflecting surfaces being symmetrical with one another with respect to a plane defined by said roll axis and a yaw axis of the device, said air flow generator comprising at least two axial fans having axes which are substantially parallel with said yaw axis, and mutually offset on said roll axis, said axial fans being mounted in said load-bearing structure, and each drawing ambient air via a respective intake opening arranged in an upper face of said load-bearing structure, using at least one multi-blade rotor driven in rotation about an axis of a corresponding axial fan and faired in a flow path with a circular cross-section extending said inlet opening towards an inside of said load-bearing structure, wherein said at least two axial fans each comprise at least two stages having pluralities of blades, one of which is said multi-blade rotor mobile in rotation about the corresponding axis, and the lift-generating device comprises, downstream of each of said at least two axial fans, an air distributer-diffuser, consisting of two adjacent semi-distributors, symmetrical with one another with respect to a plane defined by said axis of said corresponding axial fan and said roll axis, each semi-distributor delimiting a curved duct having an inlet opening receiving one of two halves of the air flow leaving said corresponding axial fan, on a side of respectively one of said two longitudinal deflecting surfaces, and guiding the air that passes through said curved duct to an outlet opening incorporated in respectively one of two lateral faces of said load-bearing structure by means of a plurality of channels extending at least over a portion of a length of said curved duct and delimited by deflecting partitions formed by generatrices parallel with said roll axis, and towards said longitudinal deflecting surface situated on a same side as said semi-distributor, so that an air flow drawn in by each said axial fan is divided into two halves, the majority of each of which is laterally blown over respectively one of said two longitudinal deflecting surfaces.

2. The device according to claim 1 , comprising successively, from a front to a rear of said load-bearing structure, and centred in a plane of symmetry defined by said roll and yaw axes of the device, a series of said at least two axial fans each cooperating with an air distributor-diffuser, followed or preceded by at least one axial fan with an axial flow outlet, the flow of which passes through said load-bearing structure from top to bottom.

3. The device according to claim 2 , wherein said axial fan with an axial flow outlet has an axis parallel with said yaw axis and has an outlet section situated in the vertical extension of an inlet section, with a ratio between said outlet section and said inlet section that is greater than 1.

4. The device according to claim 2 , wherein at least one axial fan is fitted with a least one propeller having variable-pitch and adjustable blades, and driven in rotation at a constant nominal speed.

5. The device according to claim 4 , wherein all said axial fans are driven by a drive system with fixed drive ratios, and a thrust of at least one axial fan with variable-pitch propeller is adjustable by controlling the pitch, in order to contribute to balancing the attitude of the device.

6. The device according to claim 1 , wherein an air flow generated by each axial fan with air distributor-diffuser is directed to each side of said load-bearing structure with an outward angular orientation, an angle between the direction of said flow and a plane defined by said roll and yaw axes of the device being situated between 5° and 20°.

7. The device according to claim 1 , wherein a radius of at least one axial fan with air distributor-diffuser is greater than a distance between a low point of said outlet opening of said air flow of said air distributor-diffuser, and a median plane of symmetry of the device, defined by said roll and yaw axes of the device.

8. The device according to claim 1 , wherein at least one portion of said longitudinal deflecting surfaces extends longitudinally in a substantially parallel fashion to said roll axis over a length greater than or equal to the sum of diameters of said fans with distributor-diffuser.

9. The device according to claim 1 , wherein at least one axial fan comprises two multi-blade rotors that are coaxial and contra-rotating about a common axis.

10. The device according to claim 1 , wherein on at least one axial fan with distributor-diffuser, a flow rectifier is mounted between said at least one multi-blade rotor and said air distributor-diffuser, said rectifier including a plurality of fixed vanes, which rectify an air flow at said outlet of said fan substantially parallel with said axis of said axial fan, said fixed vanes extending radially between an annular hub through which at least one drive shaft of said at least one multi-blade rotor passes, and a circular peripheral rim, coaxial with said annular hub about said axis of said fan and fixed to said load-bearing structure.

11. The device according to claim 1 , wherein, on at least one axial fan with distributor-diffuser, a flow distributor-deflector is mounted upstream, above said at least one multi-blade rotor, said flow distributor-deflector including a plurality of radial fixed vanes, which deflect an air flow at an inlet of said axial fan so that the sum of deflected flows due to the presence of said distributor-deflector and said at least one multi-blade rotor is substantially zero so that the air flow has an orientation substantially parallel with said axis of said axial fan, at said outlet of said axial fan.

12. The device according to claim 1 , wherein an area of the cross-section of said curved duct, perpendicular to a local direction of flow of air in said curved duct, is substantially constant so that a ratio of said area of the cross-section of said outlet opening to an area of the section of said inlet opening is comprised between substantially 1 and substantially 2.

13. The device according to claim 1 , wherein a shape of the cross-section of said curved duct develops progressively from a semi-circular shape at said inlet opening, in a plane substantially perpendicular to said axis of the corresponding fan, to a substantially ovoid shape in a direction substantially parallel with said roll axis, at said outlet opening, in a plane substantially parallel with said axis of said fan on said axis of said fan.

14. The device according to claim 1 , wherein a shape of said outlet opening of said curved duct is substantially rectangular.

15. The device according to claim 1 , wherein said curved duct is made up, between a semi-circular inlet opening and said outlet opening, of a curved upstream portion the cross-sections of which are substantially semi-elliptical, and comprising said plurality of deflecting partitions for guiding the air flow passing through said duct, and a downstream portion, without a deflecting partition, and substantially straight between a last, substantially semi-elliptical section, of said upstream portion and said outlet opening.

16. The device according to claim 1

Assignees

• Hutchinson

Inventors

• Simon Jean-Michel
• Andre Sébastien
• Dominiak Christophe

Classifications

• B64C29/0025 Primary

  the propellers being fixed relative to the fuselage · CPC title