Rhombohedral hydrofoil and craft comprising same

Abstract

The rhombohedral hydrofoil ( 20 ) for a craft travelling parallel to an axis ( 46 ) has a plane of symmetry and comprises front wings ( 21, 22 ) that are connected to one another and rear wings ( 25, 26 ) that are connected to one another. The end of each front wing that is furthest from the junction of the front wings with one another is connected to one end of a rear wing which is the end furthest from the junction of the rear wings with one another. This assembly of wings has a first orthogonal projection onto a plane referred to as “vertical” perpendicular to the axis of travel, this projection having the shape of a quadrilateral having an obtuse angle at the junction of the front wings with one another, an obtuse angle at the junction of the rear wings with one another, and two acute angles at the junction of a front wing with a rear wing. This assembly of wings has a second orthogonal projection onto a plane referred to as “horizontal” orthogonal to the plane of symmetry and having an axis parallel to the axis of travel, this projection having the shape of a quadrilateral having only angles with magnitudes smaller than 180 degrees.

1 . Rhombohedral hydrofoil ( 20 ,  50 ) for mounting on a lower mast ( 45 ,  105 ) of a craft ( 40 ) travelling in a direction parallel to an axis ( 46 ), this hydrofoil having a plane of symmetry and comprising, in this direction, front wings farther from the craft ( 21 ,  22 ,  53 ,  54 ) that are connected to one another, and rear wings closer to the craft ( 25 ,  26 ,  55 ,  56 ) that are connected to one another, characterised in that:
 the end of each front wing that is farthest from the junction of the front wings with one another is connected to one end of a rear wing which is the end farthest from the junction of the rear wings with one another;   this assembly ( 52 ) of wings has a first orthogonal projection onto a plane referred to as “vertical” perpendicular to the axis of travel, this projection having the shape of a quadrilateral having an obtuse angle at the junction of the front wings with one another, an obtuse angle at the junction of the rear wings with one another, and two acute angles at the junction of a front wing with a rear wing;   this assembly of wings has a second orthogonal projection onto a plane referred to as “horizontal” orthogonal to the plane of symmetry and having an axis parallel to the axis of travel, this projection having the shape of a quadrilateral having only angles with magnitudes smaller than 180 degrees; and   the front wings have a lift profile.   
     
     
         2 . Hydrofoil ( 20 ,  50 ) according to  claim 1 , which also comprises a body ( 32 ,  51 ) that comprises:
 a fastening for the lower mast ( 45 ,  105 ) of the craft;   a wing-root and junction support ( 23 ,  24 ,  57 ) for the front wings ( 21 ,  22 ,  53 ,  54 ); and   a wing-root and junction support ( 31 ,  58 ) for the rear wings ( 25 ,  26 ,  55 ,  56 ), the front and rear wing-root supports being respectively positioned either side of this body in the plane of symmetry of the hydrofoil.   
     
     
         3 . Hydrofoil ( 20 ,  50 ) according to  claim 2 , wherein the body ( 32 ,  51 ) of the hydrofoil comprises a ballast. 
     
     
         4 . Hydrofoil ( 20 ,  50 ) according to  claim 2 , wherein the body ( 32 ,  51 ) of the hydrofoil comprises a ballast tank. 
     
     
         5 . Hydrofoil ( 20 ,  50 ) according to  claim 1 , which comprises, at least on each wing ( 25 ,  26 ,  53 ,  54 ,  55 ,  56 ) of a pair of wings, at least one sidewall ( 29 ,  30 ,  63  to  66 ,  73  to  76 ) actuated by an actuator. 
     
     
         6 . Hydrofoil ( 20 ,  50 ) according to  claim 1 , wherein, at each junction of the front and rear wing ends, a vertical surface ( 27 ,  28 ,  78 ) for closing these wing ends is positioned. 
     
     
         7 . Hydrofoil ( 50 ) according to  claim 1 , wherein the rear wings have a spoiler profile. 
     
     
         8 . Hydrofoil ( 20 ) according to  claim 1 , wherein the rear wings have a lift profile. 
     
     
         9 . Hydrofoil ( 50 ) according to  claim 2  wherein:
 one end of each front wing ( 53 ,  54 ) is articulated to one end of a rear wing ( 55 ,  56 ); and 
 at least one of the wing-root supports ( 57 ,  58 ) can move along the body of the hydrofoil. 
 
     
     
         10 . Hydrofoil ( 50 ) according to  claim 9 , wherein the length of the rear wings is strictly shorter than the length of the front wings, the angle formed between the main longitudinal axis of the body of the hydrofoil and the main axis of the rear wings therefore being more obtuse than the angle formed between the main longitudinal axis of the body of the hydrofoil and the main axis of the front wings. 
     
     
         11 . Hydrofoil ( 50 ) according to  claim 9 , wherein at least one of the wing-root supports is configured to come closer to the other wing-root support so that the front wings form the hypotenuses of right-angle triangles formed by the front wings, the rear wings and the body of the hydrofoil, the main axis of each of the rear wings being, in these right-angle triangles, perpendicular to the main longitudinal axis of the body of the hydrofoil. 
     
     
         12 . Hydrofoil ( 50 ) according to  claim 9 , wherein at least one of the wing-root supports is configured to come closer to the other wing-root support so that the front wings and the rear wings are in swept-back configurations. Thanks to these provisions, the sweep of the front wings can be increased and the span reduced, in particular for flight configurations at the highest speed. 
     
     
         13 . Hydrofoil ( 50 ) according to  claim 9 , wherein at least one of the wing-root supports is configured to move away from the other wing-root support so that the hydrofoil's span is less than the sum of four times the maximum width of the front wings and the rear wings, firstly, and the width of the body of the hydrofoil, secondly. 
     
     
         14 . Hydrofoil ( 50 ) according to  claim 9 , wherein each of the wing-root supports can move along the body of the hydrofoil. Thanks to these provisions, the geometric configuration of the wing structure can be adjusted for any distribution of mass or thrust. 
     
     
         15 . Hydrofoil ( 50 ) according to  claim 9 , wherein at least one wing-root support is put into motion by a motor, a control unit actuating this motor. Thanks to these provisions, the centre of thrust of the wing structure can be moved from front to back on the body of the hydrofoil, independently of the geometry of the wing structure dictated by the distance between the wing-root supports. 
     
     
         16 . Hydrofoil ( 50 ) according to  claim 9 , wherein at least one front wing-root support comprises at least one pivot. 
     
     
         17 . Hydrofoil ( 50 ) according to  claim 9 , wherein a rod inside one of the wings keeps the main plane of the vertical surfaces for closing wing ends parallel to the main axis of the body of the hydrofoil. 
     
     
         18 . Hydrofoil ( 50 ) according to  claim 9 , wherein the junctions of the front and rear wing ends comprise pivots. 
     
     
         19 . Craft ( 40 ,  100 ) comprising a hydrofoil ( 20 ,  50 ) according to  claim 1 . 
     
     
         20 . (canceled) 
     
     
         21 . Craft ( 40 ,  100 ) according to  claim 19 , which comprises means for morphing the wing structure, to alter the inclination of the wings' axes of rotation and cause a variation of incidence, the adjustment means ( 51 ) controlling the morphing means.