EP3615409B1 - Surface vessel with motorised mechanical propulsion having a fusiform hull and ballasted keel - Google Patents

Description

TECHNICAL FIELD TO WHICH THE INVENTION RELATES

The present invention generally relates to the field of surface ships. It relates more particularly to a motorized mechanically propelled surface vessel with a spindle-shaped hull and a ballasted keel. The ship is more particularly intended for the production of a drone used in underwater measurement operations and in particular by sonars and/or sounders.

TECHNOLOGICAL BACKGROUND

Surface ships intended for underwater measurement operations by sonars and/or sounders are known. They generally include sonar and/or sounder equipment arranged under the hull, in particular in the bulbs of the hull, and for the rest they are conventional vessels with crew on board.

We also know the following documents with US2014/261126 disclosing a self-contained, unmanned, wind-powered vessel through a wing erected on the vessel. The document US 2015/210359 which discloses a surface machine that can also move as a submersible machine, and in surface activity, it is a wing that makes it move forward thanks to the wind. These documents do not give any precise indication of the dimensions and performance of these machines. The document JP 2013 035 361 discloses a wind-powered vessel which is not intended to travel at high speeds and which has an entirely different purpose than the vessel of the present application. We also know the documents US 8,154,953 B1 , ES 2 528 566 A1 , US 2007/051292 A1 and US 5,860,381 .

OBJECT OF THE INVENTION

The present invention proposes a vessel specially dedicated to underwater measurements and which can be used as an autonomous drone, with or without crew or pilot on board, remotely controlled and/or preprogrammed for its course and its evolutions.

More particularly, there is provided according to the invention a vessel according to claim 1.

• le navire est un drone comportant des équipements de navigation informatiques télécommandés et/ou préprogrammés,
• le navire est sans pilote à bord,
• la propulsion mécanique motorisée est mixte, au moins un moteur à combustion interne actionnant au moins un générateur électrique qui à son tour alimente au moins un moteur électrique actionnant directement une ou plusieurs hélices ou une ou plusieurs turbines, le moteur à combustion interne actionnant donc indirectement une ou plusieurs hélices ou une ou plusieurs turbines,
• dans le cas d'une propulsion mécanique motorisée par moteur électrique, le navire comporte en outre des batteries rechargeables stockant de l'énergie électrique destinée au(x) moteur(s) électrique(s) actionnant directement une ou plusieurs hélices ou une ou plusieurs turbines,
• le navire comporte sur son pont des cellules photovoltaïques destinées à recharger les batteries rechargeables,
• le navire est destiné à réaliser des mesures acoustiques et il comporte des systèmes de mesures acoustiques comportant des transducteurs d'émission et de réception d'ondes acoustiques, et au moins les transducteurs d'émission et de réception d'ondes acoustiques sont disposés dans le bulbe de la quille,
• le navire comporte une centrale de mesure d'attitude comportant des capteurs de mesure d'attitude et au moins des capteurs de mesure d'attitude sont disposés dans le bulbe de la quille,
• la quille est interchangeable,
• la quille est réglable en hauteur sous la coque afin de pouvoir régler la profondeur du bulbe par rapport à la coque,
• la coque fait office de flotteur,
• la partie de liaison de la quille a une longueur sensiblement identique sur toute sa hauteur,
• la partie de liaison de la quille a une largeur maximale sensiblement identique sur toute sa hauteur,
• le rapport de la largeur maximale de la partie de liaison sur la largeur maximale du bulbe est compris entre 0,05 et 0,5.

Other non-limiting and advantageous characteristics of the vessel in accordance with the invention, taken individually or in all technically possible combinations, are the following:

• the vessel is a drone comprising remote-controlled and/or pre-programmed computer navigation equipment,
• the vessel is unmanned on board,
• the motorized mechanical propulsion is mixed, at least one internal combustion engine actuating at least one electric generator which in turn supplies at least one electric motor actuating directly one or more propellers or one or more turbines, the internal combustion engine therefore actuating indirectly one or more propellers or one or more turbines,
• in the case of mechanical propulsion motorized by an electric motor, the vessel further comprises rechargeable batteries storing electrical energy intended for the electric motor(s) directly driving one or more propellers or one or more impellers,
• the ship has on its deck photovoltaic cells intended to recharge the rechargeable batteries,
• the ship is intended to carry out acoustic measurements and it comprises acoustic measurement systems comprising transducers for transmitting and receiving acoustic waves, and at least the transducers for transmitting and receiving acoustic waves are arranged in the keel bulb,
• the ship comprises an attitude measurement unit comprising attitude measurement sensors and at least attitude measurement sensors are arranged in the bulb of the keel,
• the keel is interchangeable,
• the keel is adjustable in height under the hull in order to be able to adjust the depth of the bulb in relation to the hull,
• the hull acts as a float,
• the connecting part of the keel has a substantially identical length over its entire height,
• the connecting part of the keel has a substantially identical maximum width over the entire his height,
• the ratio of the maximum width of the connecting part to the maximum width of the bulb is between 0.05 and 0.5.

DETAILED DESCRIPTION OF AN EXAMPLE OF REALIZATION

The following description with reference to the appended drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

• de la figure 1, le navire exemplifié est vu de côté, c'est-à-dire latéralement,
• de la figure 2, le navire est vu en coupe verticale transversale passant par la quille, et
• de la figure 3, le navire est vu de dessus.

On the attached drawings:

• of the figure 1 , the exemplified ship is seen from the side, i.e. laterally,
• of the figure 2 , the ship is seen in transverse vertical section passing through the keel, and
• of the picture 3 , the ship is seen from above.

Device

On the figure 1 , there is shown the mechanically propelled surface ship 1 of the invention which comprises a very narrow spindle-shaped hull 2 . This very narrow hull does not give transverse stability to the ship 1 which has a very tapered shape and which means that with this tapered bow hull, a wave-piercing ship is obtained. At the lower part of the hull 2 is installed a keel 3 with a bulb 6. The bulb 6 being at the lower end of the keel, it is connected to the hull by a connecting part 5 of the keel 3. The hull , the topsides and deck 4 are designed to be of the "piercing wave" type, i.e. the distribution of volumes and the water entry angles are designed to minimize the vertical thrust when meeting of the hull with the waves (Archimedean thrust and dynamic pressures).

The keel 3 with bulb 6 comprises, preferably in the bulb 6, a ballast which gives transverse stability to the vessel 1. This ballast is a specific heavy material, for example lead or uranium, and/or corresponds to equipment, in particular meters, installed in the bulb 6.

The surface vessel 1 of the invention therefore differs from mechanically propelled boats which have a geometry which provides them with form stability aimed at maintaining the horizontal trim of the boat during the displacement of the masses carried and the movements generated by the sea or the ocean.

The elements of the ship above the waterline and in particular those on the deck are of reduced height so that the center of gravity of the ship with its keel is very low. The ship does not have a sail, mast or rigging or any other equipment intended to use the force of the wind. In practice, it is designed to have little wind resistance. It will therefore have a weak radar echo due to its shape, size and low height of the emerged parts. Its shell and the materials it is made of can be chosen according to the needs. For example metals to keep a radar echo or composite materials, in particular fiberglass, in the opposite case. Although the ship does not use the wind for its propulsion and therefore does not include a mast or other overhead appendage dedicated to the use of the wind for propulsion, the vessel may however include a mast used in particular to carry radio equipment and /or optics and/or wind generator and/or sensors, as well as to raise any air intakes useful for certain operating modes of the drone as high as possible.

Thanks to the very narrow shape of the hull 2 also visible on the figures 2 and 3 , the ship 1 has a very low resistance to progress with regard to its length. Hull 2 with keel 3 minimizes pitching movements. The hull 2 is capable of exceeding the limit hull speed with very little energy and of going into overspeed without however being of so-called “planing” shapes.

More specifically, ship 1 has a configuration that allows it to navigate at speeds corresponding to a Froude number greater than 0.45. Remember that the Froude number is the ratio between the length of the hull and the speed. This hull length is less than 20 meters and greater than 2.5 meters depending on the embodiment and the maximum speed, still depending on the embodiment, can reach 30 knots. Due to the shapes of the water inlets and outlets of this vessel, which is a wave-piercing vessel, the length of the hull is in practice identical or almost identical to the total length of the vessel.

Vessel 1, whose total length is less than 20 meters and which has a minimum length of at least 2.5 meters, has a total width to total length ratio of less than 0.2.

Compared to conventional mechanically propelled vessels which do not need it, and in particular high speed vessels for which it would be a handicap, it features a weighted keel. This keel is useful for the stability of the present vessel because the latter, which has a very tapered/fusiform shape, has no or almost no transverse stability of shape, unlike conventional mechanically propelled vessels. It is recalled that this vessel is intended to carry out acoustic measurements in the water and that it is not intended to "fly" above the water, nor to "hover", its keel comprising extent to remain in the water, their movements to be damped as much as possible. It must therefore be able to pierce the waves while sailing at high speed and with reduced energy expenditure.

The ship 1 also comprises in this example a rudder 7.

The ship 1, which is not a scale model of an existing ship, is a drone intended to carry out acoustic measurements, the acoustic measurement systems, in particular the transducers for transmitting and receiving acoustic waves, are arranged in the bulb 6 of the keel 3. In addition, the keel 3, in particular its bulb 6, also comprises an attitude unit which allows precise corrections of the acoustic measurements of the fact that this attitude unit is positioned as close as possible to the acoustic transducers.

This vessel is autonomous in that it comprises mechanical means of propulsion and an internal energy source. It is therefore not a towed device and/or connected by a cable to another vessel or other equipment, whether floating or not.

Thanks to the shape of the hull 2, the resistance to progress is reduced both in calm water and in rough water and a reduction in the movements generated on the ship 1 by the agitation of the waves is obtained. The shape of the vessel 1 and of its keel 3 makes it possible to improve the flows around the acoustic transducers and avoids the formation of bubbles having a masking effect at the level of the acoustic transducers. This results in a reduction in the "noise" interfering with acoustic measurements in traditional ships.

This drone is therefore mechanically propelled and an electric or internal combustion or even mixed motor is used, driving one or more propellers or one or more turbines.

In a preferred embodiment, the keel 3 is removable and interchangeable. In addition, in an advanced mode, the keel 3 can be more or less raised and it is therefore liftable, in order to be able to reduce the draft of the boat because the keel can be positioned at different heights thus varying the ship's draft.

It is also preferred that the bulb 6 of the keel 3 is interchangeable with the keel so that the drone can be used with different configurations of acoustic transducers.

Claims (8)

1. A mechanically propelled surface vessel (1) having a fusiform hull (2) and a keel (3) in the lower part of the hull, the hull (2) being elongated in a longitudinal direction of the vessel, the keel (3) having at its lower end a bulb (6) linked to the hull by a linking part (5) of the keel, the maximum width of the linking part (5) being smaller than the maximum width of the bulb (6), the maximum length of the linking part (5) being smaller than the maximum length of the bulb (6), said lengths and widths being considered in the longitudinal direction of the vessel (1) and in a horizontal transverse direction perpendicular to the longitudinal direction, respectively,

   wherein the hull (2) has total width to total length ratio of less than 0.2 and a maximum length of less than 20 metres and a minimum length of at least 2.5 metres, and with a ratio of the hull height above the waterline and except possible appendices thereof to the hull height under the waterline lower than 0.8 and higher than 0.1, and wherein the mechanical propulsion includes at least one electrical motor and/or internal combustion engine and operating directly or indirectly one or several propellers or one or several turbines, the vessel having no sail, mast or rigging, or any other equipment intended to use the force of the wind,

   wherein the keel is ballasted and

   wherein the vessel is of the wave-piercing type and is configured to sail at speeds corresponding to a Froude number higher than 0.45 without however being of the "planning" type.
2. The vessel (1) according to claim 1, wherein in that it is a drone containing remote-controlled and/or pre-programmed computer navigation equipment.
3. The vessel (1) according to any one of the preceding claims, wherein it is intended for acoustic measurements and contains acoustic measurement systems including acoustic wave transmission and reception transducers, and wherein at least the acoustic wave transmission and reception transducers are arranged in the bulb (6) of the keel (3).
4. The vessel (1) according to any one of the preceding claims, wherein it contains an attitude measurement unit including attitude measurement sensors, and wherein at least attitude measurement sensors are arranged in the bulb (6) of the keel (3).
5. The vessel (1) according to any one of the preceding claims, wherein the keel (3) is interchangeable.
6. The vessel (1) according to any one of the preceding claims, wherein the keel (3) is adjustable in height under the hull (2) so that the depth of the bulb (6) with respect to the hull (2) can be adjusted.
7. The vessel (1) according to any one of the preceding claims, wherein the linking part (5) of the keel (3) has a substantially identical length over the whole height thereof.
8. The vessel (1) according to any one of the preceding claims, wherein the ratio of the maximum width of the linking part to the maximum width of the bulb is comprised between 0.05 and 0.5.

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