WO2006120317A1

WO2006120317A1 - Multi-hull boat

Info

Publication number: WO2006120317A1
Application number: PCT/FR2006/000980
Authority: WO
Inventors: Dominique Pink; Benny Diricx; Patrice Culot
Original assignee: CAPPELEN, Pontus, Diderik, Auguste
Priority date: 2005-05-11
Filing date: 2006-05-02
Publication date: 2006-11-16
Also published as: FR2885593A1; NO20076373L; FR2885593B1; EP1907272A1; AU2006245650A1

Abstract

The inventive multi-hull boat (2) comprises at least four parallel hulls, wherein the central hulls (3) are shorter than the lateral hulls (4), the front end of each central hull is backwardly shifted with respect to the front ends of the lateral hulls. Said invention is characterised in that the width of each hull (3, 4) increases away from the front end until a value of 60-70 % the length thereof is attained and, afterwards, slightly decreases to the rear end thereof, wherein the maximum width of the hulls is aligned on the same cross-sectional plane (E) of the boat.

Description

Multihull boat

The present invention relates to a multihull boat. There are boats with several parallel hulls. Double-hulled boats are called catamarans. There are also boats with three hulls, called trimarans, in which the central hull is longer than the side hulls, these hulls playing in fact much more the role of stabilizing floats that actually hulls.

It is also known from document FR 2 586 001 to make a boat comprising four hulls, whose central hulls are shorter than the lateral hulls, and whose front end of each central hull is set back from the front ends. side hulls while the rear ends of each hull are arranged in the same plane transverse to the axis of the boat.

The fact that the side hulls are longer than the central hulls and protrude from them at the front of the boat ensures the formation of a kind of funnel, forcing the air to rush inside the tunnels delimited between the different hulls. Such a structure makes it possible to obtain a good lift of the boat.

The document FR 2 661 652 describes a boat similar to that described in document FR 2 586 001 but which differs from the latter in that the width of each hull increases, continuously, from its front end to its rear end.

Thus, the passage section of the tunnels delimited between the different hulls is reduced from the front to the rear of the boat, the air pressure increases from the front to Panière, improving the lift of the boat, promoting the planing of this, which limits the value of the immersed volume, and therefore allows to obtain good speed performance with reduced motorization.

However, tests have shown that air-water turbulence appears on the central hulls from a speed above 40 knots, making the boat unusable above this speed.

The present invention therefore aims to remedy this drawback. The technical problem underlying the invention is the realization of a boat comprising at least four parallel hulls that can provide high speed performance using means of propulsion of reduced power, while avoiding the creation of air-water turbulence.

For this purpose, the invention relates to a multihull boat, comprising at least four parallel hulls, the central hulls being shorter than the side hulls, the front end of each central hull being arranged set back from the front ends of the hulls , characterized in that each shell has a width which increases from its front end to a value between 60 and 70% of its length and then decreases slightly to its rear end, the maximum width of the shells being aligned on a same plane transverse to the boat.

Thus, the passage section of each tunnel formed between two adjacent hulls is reduced from the front of the boat to a value between 60 and 70% of its length, then increases slightly to the rear of the boat. This results, in operation of the boat, a compression of the air entering the tunnels of the front of the boat up to 60 to 70% of the length of each tunnel, then a slight decompression of the air up to the back of the boat.

This compression of the air on the front of the tunnels ensures excellent lift of the boat, thus promoting the planing of the latter, which limits the value of the immersed volume, and therefore allows to obtain excellent performance with a motorization quite reduced.

This decompresson of the air in the rear part of the tunnels avoids the appearance of air-water turbulence. Thus, given this shape of the hulls, the compression of the air is accompanied by a perfectly laminar flow, even at very high speed.

The boat according to the invention thus makes it possible to avoid the appearance of air-water turbulence, even at very high speed. According to another characteristic of the invention, the central shells are thinner than the lateral shells, the distance between the median longitudinal axis of two adjacent shells being constant.

As a result, the central tunnel or tunnels are wider than the two outer tunnels. This added to the fact that the maximum width of the hulls is aligned in the same plane transverse to the axis of the boat makes it possible to balance the internal forces of compression of the air in the tunnels. This results in a similar pressure in each tunnel, which improves the aerodynamic lift of the boat.

Advantageously and according to another characteristic of the invention, the side walls of each shell are substantially inclined from the inside to the outside and from the bottom upwards.

According to another characteristic of the invention, the bottom of each shell is substantially flat from its front end to a value between 30 and 45% of its length, then has a V-section to its rear end, the bottom of each shell being, in its V part, inclined from the front to the rear and from top to bottom forming with the horizontal an angle between 0.7 and 3 °.

Given this inclination, when the boat begins to weigh under the action of a calculated thrust, the V-shaped part of the bottom of each shell forms with the horizontal angle advantageously between 1, 2 and 3.5 °. This results, during navigation, a good positioning of the engines, and therefore the possibility of using surface propellant type hydropropulseur, as well as an improvement of the longitudinal stability of the boat at full power and in particular in a straight line. Advantageously, the bottom of each shell is connected to each side wall thereof, by a flat surface of intermediate inclination, forming a chamfer, the height of this inclined surface, decreasing regularly from rear to front depending from the inclination of the bottom until it vanishes at the front end of the hull. In addition, advantageously, the hulls are covered by a floor whose downwardly facing face comprises at least a first portion inclined from top to bottom and from front to rear extending from the front of the boat to at substantially half the length of the boat, and at least a second portion inclined from bottom to top and from front to rear. According to another characteristic of the invention, the downwardly facing face of the floor comprises, between the first and second inclined portions, at least one substantially horizontal intermediate portion.

Advantageously, the first inclined portion of the downwardly facing face of the floor comprises at least a first surface inclined from top to bottom and from front to rear, extended towards the rear by a second inclined surface from top to bottom and from front to rear forming with the horizontal an angle less than that of the first inclined surface.

According to another characteristic of the invention, the first inclined surface forms with the horizontal an angle between 10.5 and 11 °, the second inclined surface forms with the horizontal an angle between 1, 5 and 2 °, and the second inclined portion forms with the horizontal an angle of between 1, 5 and

2 °.

These different inclinations of the face of the floor covering the hulls, facing downwards, facing the water, offer a profile improving the aerodynamic lift of the boat.

Indeed, it follows from this last feature that the height of each tunnel formed between two adjacent hulls decreases from the front to the center of the boat which further increases the phenomenon of air compression, before releasing this air compression. . According to another characteristic of the invention, the boat comprises at the front means for modifying the passage section of the air entering the tunnels delimited by two adjacent hulls and stabilize the boat at high speed, and at the rear means for modifying the passage section of the air leaving the tunnels. These means facilitate the lifting of the boat at low speed, and instead to keep it in contact with water at high speed. This results in a better stability of the boat and an improvement of the conditions of its piloting.

Advantageously, the means for modifying the passage section of the air entering the tunnels delimited by two adjacent shells comprise a flap mounted longitudinally sliding between the two outer shells, inclined from top to bottom and from rear to front in forming with the horizontal angle less than 16 ° and preferably 7 °, when the flap is in the advanced position. Advantageously, the means for modifying the passage section of the air leaving the tunnels delimited by two adjacent shells comprise a rear flap pivotally mounted about a horizontal axis.

According to another characteristic of the invention, at least each side hull comprises in its front part and / or in its rear part a ballast intended to receive water serving as ballast in order to adjust the attitude of the boat, whatever its speed. When the boat is stopped or at low speed, the concentration of weight on the rear, especially because of the presence of the engines at the rear, causes the inclination of the bridge from top to bottom and forward in back. Ballasts filled with water compensate for this imbalance. As the speed of the boat increases and the speed is increased by the air pressure between the hulls, it is possible to empty the ballasts to maintain a constant speed.

This boat which can comprise for example four hulls, or a larger number of hulls is advantageous given the lift characteristics it has, and which can limit the power of the engine.

In addition, it should be noted that the engine can be achieved using one or more engines, the engine can, for example, be distributed by placing an engine in each shell, which provides perfect security since in If one of the engines fails, the boat can follow its course using the other engines. Depending on the load and the navigation conditions, it is possible or not to use all motors simultaneously.

Thus, in the start-up phase, it is possible to use several engines and, when the boat is in lift position, to use, for example, only two engines that are not implemented. at maximum power.

This type of boat is equally suitable for pleasure craft, for launching type boats for the transport of passengers or for commercial vessels for the transport of vehicles or containers. In all cases, the boat sails at a speed of the order of 16 knots, beyond which the wet surface is greatly reduced since the length at the waterline during the navigation period is reduced by 3/5.

It is also envisaged other applications of this boat, for example in a medical, military or police for rapid interventions, for rapid transport from port to port, etc.

In any case the invention will be better understood with the aid of the description which follows with reference to the attached schematic drawings showing, by way of non-limiting example, an embodiment of this boat.

Figure 1 is a side view. Figure 2 is a front view. Figure 3 is a view from behind.

Figure 4 is a view from below showing the profile of the hulls. Figure 5 is a longitudinal sectional view along a tunnel delimited between two adjacent shells.

As shown in FIGS. 2 to 4, the boat 2 comprises four parallel hulls, namely two identical central hulls 3 and two identical lateral hulls 4.

As shown more particularly in FIG. 4, each central shell 3 is shorter and slightly thinner than the lateral hulls 4, and the front end of each central hull 3 is set back with respect to the front ends of the lateral hulls 4, while the rear ends of each shell 3, 4 are arranged in the same plane transverse to the axis of the boat. Figure 4 also shows that the distance between the median longitudinal axis E of two adjacent shells is constant.

Each shell 3, 4 has a width that increases from its front end to a value between 60 and 70% of its length and then reduces slightly to its rear end, the maximum width of the shells 3, 4 being aligned on the same plane F transverse to the axis of the boat.

As shown in Figure 2, the side walls 5, 6 of each shell 3, 4 are inclined from bottom to top and from the inside to the outside.

As shown in Figures 1 and 2, the bottom 7 of each shell 3, 4 is substantially flat on a little less than half of its length from its front end, then has a V-section to its rear end. The inclined surfaces forming the V-shaped part of the bottom of each hull have a height which increases steadily up to the rear of the boat. As a result, in its V part, the bottom 7 of each shell 3, 4 is inclined from the front to the back and from top to bottom. Preferably, in its V-shaped part, the bottom 7 of each shell 3, 4 forms with the horizontal an angle between

0.7 and 3 °.

The bottom 7 of each shell is connected to each side wall 5, 6 thereof, by a flat surface 8 of intermediate inclination, forming a chamfer, the height of this inclined surface 8, decreasing regularly by the rear to the front according to the inclination of the bottom 7, until canceling at the front end of the hull.

As shown in Figure 5, each side shell 4 and central 3 has at its front end a tapered wall and concave 9 inclined from top to bottom and from front to rear. The shape of this front profile improves the cut of the wave, thus avoiding the rebound of the boat on the back of it.

The various shells 3, 4 are assembled to each other by a floor 10 whose face 11 facing down has a first portion 12 inclined from top to bottom and from front to rear extending from the front of the boat to substantially half the length of the boat, and a second portion 13 inclined from bottom to top and from front to rear.

The inclined portion 12 has a first surface 14 inclined from top to bottom and from front to rear, forming with the horizontal an angle A of between 10.5 and 11 °, and a second surface 15 inclined from top to bottom. down and from the front to the rear, forming with the horizontal an angle B between

1, 5 and 2 °.

The second surface 15 is extended rearwardly by an intermediate portion 16 substantially horizontal, thus forming with the horizontal angle C substantially zero.

The second inclined portion 13 forms with the horizontal an angle D between 1, 5 and 2 °.

The value of the angles A, B, C, D makes it possible to obtain sufficient compression of the air in the various tunnels 17 delimited by the shells, while avoiding an overpressure between the shells at certain speeds such as 40, 45 and 50 nodes.

It should be noted that the stability of the boat, in all cases of figures, is regulated by a front flap 18 disposed on the front end of the boat, on the side facing upwards of the hull connecting floor, and by a flap rear 19 disposed at the rear end of the boat, on the side facing down the hull connecting floor, the front flap and the rear flap having a width substantially equal to the width of the boat.

The front flap 18 is inclined from top to bottom and from rear to front and forms with the horizontal angle less than 16 ° and preferably equal The front flap 18 is associated with means for adjusting its position intended to slide longitudinally the flap 18 forward so that it comes progressively opposite the entrance of the tunnels 17, as the speed increases. of the boat increases. The front flap 18 thus reduces the passage section of the air entering the tunnels, which limits the air compression in high-speed tunnels.

This adjustment of the position of the front flap 18 also makes it possible to improve the aero-dynamic support on the flap, which prevents the front of the boat from being lifted at a high speed.

The rear flap 19 is articulated at its front end around a horizontal axis, and is associated with means for adjusting its vertical inclination, for example a jack, in order to close more or less the output of the tunnels 17. The flap the front and the rear flap can be controlled in synchronization to facilitate the lifting of the boat at low speed, and conversely to keep it in contact with water at high speed.

This control in synchronization of the front flap and the rear flap ensures stability of the boat but also facilitates the steering of the boat. It should be noted that at startup, the rear flap is in the low position, it forms with the horizontal an angle substantially equal to 10 °, the opening of the rear flap being progressive up to 40 knots. The speed of 50-52 knots is reached, the tailgate is fully open and the position of the front flap is adjusted automatically according to the tilt of the boat and compression between the hulls.

Each hull has in its front part a ballast (not shown in the figures) intended to receive ballast water in order to maintain the trim of the boat, the ballast emptying or filling depending on the speed of navigation of the boat . In fact, each ballast is used primarily for the balancing of the boat, before the departure of the boat or when it returns to port.

In operation, once the speed of 46 knots reached, these ballasts are slowly empty until the cruising speed of 56- 58 knots, to facilitate the lift of the boat. As is apparent from the foregoing, the invention brings a great improvement to the existing technique by providing a design boat simple, offering very high performance, with a reduced power motor.

As goes without saying the invention is not limited to the sole embodiment of this boat described above by way of example, it embraces on the contrary all variants. This is how the number of hulls could be different.

Claims

1. Multihull boat (2), comprising at least four parallel hulls, the central hulls (3) being shorter than the side hulls (4), the front end of each central hull being set back from the front ends of the hulls lateral hulls, characterized in that each hull (3, 4) has a width which increases from its front end to a value between 60 and 70% of its length and then decreases slightly to its rear end, the width maximum hulls being aligned on the same plane (F) transverse to the boat.

2. Boat (2) according to claim 1, characterized in that the central shells (3) are thinner than the side shells (4), the distance between the central longitudinal axis (E) of two adjacent shells being constant.

3. Boat (2) according to any one of claims 1 and 2, characterized in that the side walls (5, 6) of each shell (3, 4) are substantially inclined from the inside to the outside and bottom up.

4. Boat (2) according to any one of claims 1 to 3, characterized in that the bottom (7) of each shell (3, 4) is substantially flat from its front end to a value between 30 and 45% of its length, then has a V-section to its rear end, the bottom (7) of each shell (3, 4) being, in its V-shaped part, inclined from front to rear and from top to bottom forming with the horizontal an angle between 0.7 and 3 °.

5. Boat (2) according to one of claims 1 to 4, characterized in that the bottom (7) of each shell is connected to each side wall (5, 6) thereof, by a flat surface (8 ) of inclination intermediate, forming a chamfer, the height of this inclined surface (8), decreasing regularly from the rear to the front according to the inclination of the bottom (7), until canceling to the front end of the hull.

6. Boat (2) according to one of claims 1 to 5, characterized in that the shells (3, 4) are covered by a floor (10) whose face (11) facing downwards comprises at least a first portion (12) inclined from top to bottom and from front to rear extending from the bow of the boat to substantially half the length of the boat, and at least a second inclined portion (13) of bottom up and front to back.

7. Boat (2) according to claim 6, characterized in that the face (11) facing down from the floor (10) comprises, between the first and second inclined portions (12, 13), at least one intermediate portion ( 16) substantially horizontal.

8. Boat (2) according to one of claims 6 and 7, characterized in that the first inclined portion (12) of the face (11) facing down the floor (10) comprises at least a first inclined surface ( 14) from top to bottom and from front to rear, extended rearward by a second inclined surface (15) from top to bottom and from front to rear forming a lower angle with the horizontal to that of the first inclined surface (14).

9. Boat (2) according to claim 8, characterized in that the first inclined surface (14) forms with the horizontal an angle of between 10.5 and 11 °, the second inclined surface (15) forms with the horizontal an angle between 1, 5 and 2 °, and the second inclined portion (13) forms with the horizontal an angle between 1, 5 and 2 °.

10. Boat (2) according to any one of claims 1 to 9, characterized in that it comprises at the front means (18) for changing the passage section of the air entering the tunnels (17). delimited by two adjacent hulls and stabilize the boat at high speed, and the rear means (19) to change the passage section of the air leaving the tunnels (17).

11. Boat (2) according to claim 10, characterized in that the means for modifying the passage section of the air entering the tunnels (17) delimited by two adjacent shells comprise a flap (18) slidably mounted longitudinally between the two outer shells, inclined from top to bottom and from the rear to the front forming with the horizontal angle less than 16 ° and preferably 7 °, when the flap is in the advanced position.

12. Boat (2) according to one of claims 10 and 11, characterized in that the means for modifying the passage section of the air leaving the tunnels (17) delimited by two adjacent shells comprise a rear flap (19) pivoted about a horizontal axis.

13. Boat (2) according to one of claims 1 to 12, characterized in that at least each side shell comprises in its front portion and / or in its rear portion a ballast for receiving water serving as ballast to adjust the boat's trim, regardless of speed.