WO2017221117A1 - Sail propulsion element comprising an inflatable sail with a symmetrical profile - Google Patents

Abstract

A sail propulsion element comprising an inflatable sail (2) consisting essentially of two substantially sealed adjacent surfaces (9, 10) linked to each other on the perimeter of same, thus together forming a recess (8); the element further comprising a conduit (11) disposed between the inside and the outside of the recess (8) and means for injecting air into the latter; characterised by the fact that the sail (2), once inflated, has a profile that remains permanently symmetric, regardless of the movement of the element, or the direction or strength of the wind.

Description

 VELIC PROPULSION ELEMENT COMPRISING A SAIL

INFLATABLE WITH SYMMETRIC PROFILE

Field of the invention

 The present invention is in the field of vane propulsion.

It relates more precisely an inflatable sail.

State of the art

 The use of inflatable elements for vane propulsion is known. See in particular the following patent publications: US 5,931,109, US 5,775,249, US 5,671,690, EP 2,202,144 A1 and FR 3,008,382 A1.

 Inflatable sails of the state of the art, however, have several disadvantages. In some cases the sail is only inflated initially. In this configuration it is not possible to compensate for any air leaks inside the sail. In other cases, the sail is inflated passively, by introducing air (wind) permanently in the sail. This configuration, however, has the disadvantage of not having initially a sufficiently inflated sail, especially when the wind is weak or nonexistent. General description of the invention

 The vane propulsion element according to the present invention overcomes the aforementioned problems.

It comprises an inflatable sail consisting essentially of two adjacent surfaces substantially sealed and interconnected on their periphery, forming in this way at least one cavity; the element further comprising a conduit disposed between the interior and exterior of the cavity and means for injecting air therein; the element being characterized in that the sail, once inflated, has a profile that remains permanently symmetrical, regardless of the displacement of the element, the direction or intensity of the wind. According to a variant of the invention, the element also comprises means for withdrawing air from the cavity, thus making it possible to regulate the pressure inside the cavity. These means also make it possible to empty the air which is in the cavity, prior to the storage of the sail or if it is desired to reduce the surface of the sail.

According to another variant of the invention, the surfaces are rigid.

Preferably, the air injection means (eg a turbine) operate continuously, so as to continuously inject a flow of air through at least one orifice between the two adjacent surfaces in order to move away from one another by inflation and put them in tension between multiple transverse connecting elements giving the wing once inflated its final plane shape with in its thickness the shape of a carrier aerodynamic profile. Advantageously, the pressure managed by the air injection means can be very low, typically of a few 100 Pa. It therefore requires very little energy to operate.

 The profile thus obtained is substantially symmetrical, which allows the wing to operate indifferently in both directions of advancement with respect to the wind.

The pressure generated by the air injection means can be regulated so as to be always sufficient for the wing to acquire and maintain its shape in plan and in thickness in zero wind and or strong and turbulent.

The invention also relates to a vane propulsion vehicle, e.g. ex. a sailboat, comprising a base and one or more propulsion propulsion elements as described above. Each vane propulsion element is associated with a mast which passes through the cavity of the element. In this configuration the aerodynamic forces produced by the flow of air around the profile are resumed along the rigging, at a location at the level of the transverse elements, not on the front of the profile, but substantially in the center of thrust aerodynamic which is located on the axis of symmetry of the profile, substantially to 25% of its front end, thus giving the wing a substantially neutral behavior at all operating speeds. Preferably the sail is flexible, but it can also be rigid, as indicated above.

 Any air injection system suitable for the intended purpose can be used. He can p. ex. be a turbine powered by a battery.

Advantageously, the mast can retract along its length (telescopic mast), which allows the vehicle to cross obstacles such as bridges or reduce the sail area in strong wind.

Detailed description of the invention

 The invention is described in more detail in this chapter, particularly by means of examples and figures which are briefly summarized as follows:

Figure 1 shows a vane propulsion element according to the invention, in the operating position.

 Figure 2 shows the element of Figure 1, but in the rest position.

 Figure 3 shows a front view of the element of Figure 1.

 Figure 4 shows a top view of the element of Figure 1.

 Figures 5A to 5D show different operating situations with respect to wind direction.

 Figure 6 illustrates a distribution of the resulting forces acting on the sail for a given wind angle which corresponds to the position of Figure 5B

Figure 7 shows a vane propulsion element according to the invention, with a reduced surface.

The following numerical references are used in the figures:

 1 Sailboat

 2 sailing

 3 hull

 4 Mast

 5 Cell

6 Turbine 7. Profile symmetry axis

 8. Cavity

 9. 1st surface

10.2 ^th surface

 1 1. pipe

 12. Boom

The example of FIG. 1 represents a sailboat 1 mainly comprising a hull 3, a mast 4 and a sail 2 consisting of a plurality of cells 5 interconnected by orifices (not shown), the set of cells 5 forming a single cavity 8. A partial boom 12 connects the mast 4 to the sail 2. Its dimensions are small and it is not necessary that it is rigid because unlike the terminals of the state of the art which are also used to put the sail in tension, its only function is to make easier the rotation of the sail 2 around the mast 4. In fact, in the context of the present invention, it is not necessary to equip the boat with a boom ( partial or normal).

 The sail 2 is preferably permanently inflated by means of a turbine 6 disposed in the lower part of the sail 2. A duct 1 1 connects the turbine with the interior of the cavity 8.

Figure 2 shows the sailboat of Figure 1 but with the sail 2 deflated. This configuration is obtained following the stopping of the turbine 6. The deflation can be accentuated if the operation of the turbine is reversed to induce a vacuum inside the cavity 8.

FIG. 3 represents a front view of the sailboat of FIG. 1.

 It should be noted that in Figures 1 to 3, the surfaces 9, 10 forming the sail are transparent, so as to view the mast 4. Figure 4 particularly shows the symmetry of the profile of the sail 2.

In Figure 5 the direction of the wind is represented by an arrow. In FIG. 5A, the wind is in front, with respect to the hull and the sail, the boat is stopped.

 In Figure 5B the wind side (relative to the hull, and slightly side to the sail). In this configuration it has the effect of inducing a strong forward thrust, as shown in FIG.

In Figure 5C the wind is slightly off, which induces a rise to pace of meadows.

 In Figure 5 D the wind is back from the hull. The sail 2 is oriented so as to benefit from a thrust force. The sail 2 illustrated in Figure 7 to a reduced area. More precisely, its lower part is deflated. The length of the mast 4 can be fixed or variable. She can p. ex. be reduced by means of a telescopic mast.

It should be noted that in all the aforementioned positions, the sail always has a symmetrical profile. This configuration has the particular advantage of reducing the energy to spend to maintain the sail in the desired orientation.

The pressure inside the cavity can be regulated continuously.

By increasing it, the sail is more tense and solid. This configuration can be very useful during strong wave movements or control of the sail's twist. By decreasing it, the volume of the cavity and the surface of the sail can be reduced.

The present invention is obviously not limited to the aforementioned examples but covers any variant included in the subject of the claims. Thus, the air inlet can be located in any place, p. ex. through the mast when the latter passes through the cavity. In this case, filling and emptying are done through the mast.

Claims

 claims Vela propulsion element comprising an inflatable sail (2) consisting essentially of two adjacent surfaces (9, 10) substantially sealed and interconnected on their periphery, thus forming between them at least one cavity (8) closed; the element further comprising a conduit (1 1) disposed between the inside and the outside of the cavity (8) and means for injecting air therein; characterized in that the sail (2), when inflated, has a profile that remains permanently symmetrical, regardless of the displacement of the element, the direction or intensity of the wind. An element according to claim 1 comprising means for removing air from the cavity (8).  An element according to claim 1 or 2 wherein said adjacent surfaces (9,10) are rigid.  Vessel powered vehicle (1) comprising an element according to any one of the preceding claims, a base (3) and a mast (4) secured to said base (3), characterized in that the mast (4) is disposed within the cavity (4).  Vessel propulsion vehicle (1) according to claim 4 wherein the mast (4) is located on the axis of symmetry of the profile (7), about 25% of its front end.