Hydrodynamic attachment for a ship and ship with at least one such attachment

Description

[0001] The present invention relates to ships and systems for improving their seakeeping and reducing their drag.

[0002] In particular, it concerns submerged hydrodynamic hull appendages that promote a harmonious flow of water along the hull of the ship and a reduction of wake disturbances.

[0003] We are familiar with the device of patent EP 1 5751 129 or of patent application DE 39 36 280 A1 which describes a ship comprising a hydrodynamic appendage.

[0004] The hydrodynamic appendage described consists of a rear lifting plane oriented to provide a forward-directed lifting force component.

[0005] This device, in addition to facilitating the flow of water, helps to right the vessel by applying a nearly vertical force directed upwards and forwards. To optimize the device's effect, it may be advantageous to position it at the stern of the vessel.

[0006] However, on some ships, such as military vessels, a hydrodynamic appendage positioned at the rear of the stern of the ship can be an obstacle to the launching of equipment such as towed sonars or boats, which would be done from the rear of the ship.

[0007] Indeed, these devices could collide with the hydrodynamic appendage during launching or in the event of ship movements.

[0008] In these use cases, it would be necessary to launch the equipment well beyond the area in the immediate vicinity of the hydrodynamic appendage, which implies lengthening the overhang of the launching system, which can generate strong mechanical stresses.

[0009] To avoid the aforementioned drawbacks, the invention relates to a ship according to claim 1.

[0010] The invention also relates to a vessel comprising a hydrodynamic appendage as described above, the leading edge of which is configured in such a way that it includes at least one part of convex shape.

[0011] The invention also relates to a vessel comprising a hydrodynamic appendage as described above taking the form of a chevron.

[0012] The invention also relates to a vessel comprising a hydrodynamic appendage as described above, equipped with fins at its extremities.

[0013] The invention also relates to a vessel comprising a hydrodynamic appendage as described above, the trailing edge of which includes at least one movable fin.

[0014] The invention will be better understood with the aid of the following description, made with reference to the accompanying drawings, in which: [ Fig 1 ] There figure 1 represents a ship seen from the side; Fig 2 ] There figure 2 represents an embodiment of the hydrodynamic appendage of the invention; [ Fig 3 ] There figure 3 represents another embodiment of the hydrodynamic appendage of the invention; [ Fig 4 ] There figure 4 represents yet another embodiment of the hydrodynamic appendage of the invention; [ Fig 5 ] There figure 5 represents yet another embodiment of the hydrodynamic appendage of the invention; [ Fig 6 ] There figure 6 represents yet another embodiment of the hydrodynamic appendage of the invention; [ Fig 7 ] There figure 7 represents the effect induced by the use of fins in such an appendage; and [ Fig 8 ] There figure 8 represents a vessel equipped with a hydrodynamic appendage of the invention and a device for launching a towed sonar.

[0015] The figures contain the following references: 1 denotes a hydrodynamic appendage, 2 denotes the hull of a ship, 3 denotes a ship, 4 denotes a trailing edge of the appendage, 5 denotes a leading edge of the appendage, 6 denotes the tips of the appendage, 7 denotes a concave part of the trailing edge of the appendage, 8 denotes a convex part of the leading edge of the appendage, 9 denotes the tip fins of the appendage, 10 and 11 denote movable fins of the appendage, 12 denotes the water surface, 13 denotes the stern of the ship, 14 denotes support legs of the appendage, 15 illustrates the lift generated by the appendage, 16 and 17 denote pivot axes of the fins of the appendage, 18 denotes a towed sonar deployment system, and 19 denotes a towed sonar.

[0016] There figure 1 represents a ship 3 seen from the side on a body of water 12 (sea for example). The ship's waterline (not shown) is the intersection of the hull 2 ​​with the body of water 12.

[0017] The main parts of the invention are distinguished, namely an embodiment of a hydrodynamic appendage 1 in the rear part 13 of the ship, below the waterline.

[0018] The hydrodynamic appendage 1 is mounted securely to the hull 2 ​​by means of support legs 14.

[0019] A device for launching 18 devices is located at the rear 13 of the ship 3 and allows the launching of devices such as towed sonars 19.

[0020] There figure 2 represents a first embodiment of the hydrodynamic appendage 1 of the invention, seen from above the ship not shown, with a straight leading edge 5 and a trailing edge 4 having a concave shape 7.

[0021] There figure 3 represents another embodiment of the hydrodynamic appendage 1 of the invention, seen from above the ship not shown, with a leading edge 5 taking the general shape of the trailing edge 4, the latter being composed of two straight segments.

[0022] The general shape of the hydrodynamic appendage 1 is then that of a chevron in the shape of a point whose point is directed towards the front of the ship.

[0023] There figure 4 represents another embodiment of the hydrodynamic appendage 1 of the invention, seen from below the ship not shown, with a leading edge 5 taking the general shape of the trailing edge 4, the latter taking any convex shape.

[0024] The general shape of the hydrodynamic appendage 1 is then that of a rounded chevron directed towards the front of the ship.

[0025] There figure 5 represents an improvement of the hydrodynamic appendage 1 of the invention, seen in perspective from the rear three-quarters of the ship not shown, and comprising at its two ends 6 vertical or inclined fins 9 designed on the same principle as the winglets of airplanes or hydrofoils to avoid the formation of vortices at the end of the profile of the hydrodynamic appendage.

[0026] The principle of fins for a hydrofoil is described, for example, in US document 4,050,397.

[0027] There figure 6 represents an improvement of the hydrodynamic appendage 1 of the invention, seen in perspective of the three-quarter rear of the ship not shown, and comprising on either side of the trailing edge 4 fins 10, 11 included in the shape of the hydrodynamic appendage 1, provided with at least one degree of rotational freedom about an axis 16, 17 allowing them to be raised or lowered in order to increase or decrease the lift of the left or right part of the hydrodynamic appendage 1.

[0028] There figure 7 represents the effect induced by the use of the fins 10, 11 on the lift 15 of the hydrodynamic appendage 1. When the fin 11 is raised and the fin 10 is lowered, the lift of the left part of the hydrodynamic appendage is less than that of the right part, resulting in an orientation of the lift 15 of the hydrodynamic appendage 1 to the left.

[0029] The lift 15 would be directed to the right if the aileron 11 was lowered and the aileron 10 was raised.

[0030] There figure 8 represents a ship 3 equipped with a hydrodynamic appendage 1, the object of the invention, and a device 18 for launching a towed sonar 19.

[0031] The chevron configuration of the hydrodynamic appendage 1 allows the towed sonar 19 to be launched to avoid it colliding with the hydrodynamic appendage 1 or to avoid it being hindered in its launching by the hydrodynamic appendage 1, the shape of the latter clearing a free zone directly above the launching zone of the launching device 18.

[0032] In one embodiment, the invention relates to a vessel 3 whose hull 2 ​​includes on its rear part 13 and below the waterline at least one hydrodynamic appendage 1 comprising a trailing edge 4 and a leading edge 5, the trailing edge having a concave shape in order to leave sufficient space for the deployment of a towed sonar 19 for example.

[0033] The leading edge of the hydrodynamic appendage 1 can then be straight, as on the figure 2 .

[0034] The shape of the hydrodynamic profile of the hydrodynamic appendage and its surface area are identical to a hydrodynamic appendage not having these characteristics.

[0035] Thus, the hydrodynamic performance is identical to that of a known hydrodynamic appendage.

[0036] In another embodiment, the hydrodynamic appendage 1 is chevron-shaped with a pointed tip, as on the figure 3 or rounded as on the figure 4 .

[0037] In another embodiment, the hydrodynamic appendage 1 has vertical or inclined surfaces 9 at both ends of the hydrodynamic appendage 3 to prevent the formation of vortices at the end of the profile, in the manner of the winglets of an airplane or hydrofoil.

[0038] The hydrodynamic appendage thus causes less turbulence.

[0039] In another embodiment, the hydrodynamic appendage 1 has at the trailing edge 4 fins 10, 11 allowing the lift of the hydrodynamic appendage 1 to be increased or decreased.

[0040] These fins 10, 11 can be actuated separately by devices not shown, known in the state of the art as jacks, and create a lift force 15 inclined to the right or to the left of the hydrodynamic appendage 1.

[0041] The hydrodynamic appendage 1 can then participate in the management of the roll of the ship 3 on which it is installed.

Claims

1. A ship (3) comprising a hull (2) comprising on its rear part (13) and below the waterline at least one hydrodynamic appendage (1), said appendage comprising a trailing edge (4) and a leading edge (5) and ends (6), the ends of the appendage comprise fins (9), the ship being characterized in that it comprises a launching device (18) for equipment arranged at the rear part of the ship (3), the trailing edge (4) comprising at least one concave-shaped part (7) clearing a free zone directly above the launching area of the launching device (18) in order to leave sufficient space for the launching of equipment.

2. The ship according to claim 1, characterized in that the leading edge (5) comprises at least one convex-shaped part (8).

3. The ship according to claim 2, characterized in that the leading edge (5) and the trailing edge (4) form a chevron.

4. The ship according to any one of the preceding claims, characterized in that the trailing edge (4) comprises at least one movable fin (10, 11).