Transverse propulsion device provided with inclined grid

Abstract

To provide a transverse propulsion device capable of overcoming a fault in the prior art.SOLUTION: A transverse propulsion device for vessels includes: a transverse steering tunnel 25 going though a hull 21; a tunnel wall 27; and an opening edge 26 partitioning a tunnel inlet opening 28 on a hull outside surface 210. The transverse propulsion device includes a grid 4 including a plurality of upright members 41 and a plurality of transverse members 42 making incidence on a grid surface 45. The grid 4 includes an inside transverse member end 421 continued to the tunnel wall 27 and at least one transverse member 42 existing between the outside transverse member end 422, closer to the hull outside surface 210, and the inside transverse member end 421.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lateral propulsion device for a ship.

[0002] Preferably, the present invention is directed to large ships such as container ships and cruise ships. [Background technology]

[0003] It is known in the field of ship steering that in order to perform docking and undocking maneuvers at low speeds in narrow spaces, special transverse propulsion devices with steering propellers having axes of rotation oriented transversely to the vertical longitudinal or diametrical plane of the ship are indispensable.

[0004] In order to protect the transverse propulsion devices from possible shocks, it is known to mount a grille at the entrance opening of the steering tunnel transverse to the hull in which the steering propellers are housed.

[0005] Furthermore, in order to reduce turbulence phenomena during navigation, it is known to include special closure devices, usually having movable doors arranged at the opening of the transverse steering tunnel, movable between an open position, in which they allow the water flow in the steering tunnel, and a closed position, in which they completely close the tunnel entrance opening and substantially restore the outer hull surface.

[0006] In particular, doors mounted on multiple hinges connected to the mouth of the lateral steering tunnel are known. Examples of these solutions are described in CN205819525, CN105329405, CN102381439, CN109094715, WO2019 / 220152 and GB782628. Further example embodiments are described on behalf of the applicant in international applications WO2022079655A1, WO2022079651A1 and WO2022079652A1. Steering lateral tunnel closure devices comprising a protective grid at the mouth of the lateral steering tunnel are known in the art. Examples of these solutions are described in EP2923942A1, KR20140036409A, US10988220B2 and CN111516842B. Summary of the Invention

[0007] Such laterally steered tunnel closure devices have a number of hazardous aspects known to naval designers.

[0008] The main challenges include the design of the hydrodynamic shape of the door, which aims to minimize turbulence due to the geometric discontinuity between the door and the exterior surface of the vessel while underway, and at the same time minimize its bulk in the open position, i.e. when the lateral thrusters are in operation.

[0009] At the same time, the lateral steering tunnel closing device has a complex structure, which contributes to increasing the overall weight of the ship.

[0010] Furthermore, the lateral maneuvering tunnel closure devices must be designed to minimize the potentially damaging effects of slamming, for example when the hull (typically the bow) of a ship is suddenly plunged into the water by a water surge. Such slamming, especially at high speeds, can create high pressure gradients in the lateral maneuvering tunnels that can damage the ship's plating and connections and impair the operation of doors and lateral thrusters.

[0011] Such critical aspects and the associated problems lead designers to conflicting technical solutions: on the one hand, towards a complete closure of the transverse steering tunnel inlet openings in order to better reconfigure the hydrodynamic shape of the hull, and on the other hand, towards a complete opening of the tunnel inlet openings in order to simplify and lighten the hull and eliminate the steep pressure gradient between the inside and outside of the steering tunnel.

[0012] The object of the present invention is to create a lateral propulsion device making it possible to overcome the drawbacks highlighted in the prior art solutions.

[0013] It is an object of the present invention to provide a lateral propulsion arrangement that achieves a compromise between low drag and generating turbulence during navigation while at least partially maintaining a predominantly laminar water flow along the exterior of the vessel near the lateral steering tunnel entrance opening, while simultaneously maximizing the overall weight reduction and structural complexity of the vessel.

[0014] Specifically, one of the objectives of the present invention is to create a structurally simple lateral propulsion system having a very low part count.

[0015] It is yet another object of the present invention to provide a lateral propulsion device having a very limited weight.

[0016] A further object is to provide a lateral propulsion device which allows for simplified installation and maintenance operations.

[0017] It is a further object of the present invention to prevent or attenuate the formation of high pressure gradients between the inside and outside of the lateral steering tunnels, typically due to hull slamming.

[0018] These and other objects are achieved by a ship lateral propulsion device according to claim 1. The dependent claims set out preferred embodiments which contain a series of advantageous technical effects. [Brief description of the drawings]

[0019] The features and advantages of the present invention will become apparent from the following description, its preferred embodiments, and the accompanying drawings, in which: [Figure 1] FIG. 1 shows a detail of a hull having multiple steering tunnels and a closure device associated with each steering tunnel, according to an embodiment of the present invention. [Diagram 2] FIG. 1 shows a front part of a vessel with multiple steering tunnels made in the hull and a closure device associated with one of the steering tunnels according to an embodiment of the present invention. [Diagram 3] FIG. 2 illustrates a cross-section of the hull at the lateral steering tunnel, according to one embodiment of the present invention. [Figure 4] FIG. 13 is a front view of a pair of grilles for two lateral steering tunnels aligned along the outer flow direction, according to one embodiment of the present invention. [Diagram 5] FIG. 2 illustrates a lattice of a lateral steering tunnel according to a first embodiment of the present invention. [Figure 6] FIG. 13 illustrates a lattice of a lateral steering tunnel according to a second embodiment of the present invention. [Figure 7] FIG. 13 illustrates a lattice of a lateral steering tunnel according to a third embodiment of the present invention. [Figure 8] FIG. 6 is a perspective view of the grid of FIG. 5. [Figure 9] FIG. 6 is a cross-sectional view of a hull in a substantially vertical cross section near a tunnel entrance opening of the hull according to the embodiment of FIG. 5. [Figure 10] FIG. 6 is a cross-sectional view of a vessel hull in a substantially horizontal section at a transverse steering tunnel of the vessel hull according to the embodiment of FIG. [Figure 11] FIG. 7 is a perspective view of the grid of FIG. [Figure 12] FIG. 8 is a perspective view of the grid of FIG. [Figure 13] FIG. 13 illustrates a lattice of a lateral steering tunnel according to a fourth embodiment of the present invention. [Figure 14] FIG. 14 is a cross-sectional view of the hull in a substantially horizontal section at the lateral steering tunnel according to the embodiment of FIG. [Figure 15]FIG. 13 is a perspective view of a lattice of a lateral steering tunnel according to a fifth embodiment of the present invention. [Figure 16] FIG. 16 illustrates a lattice of a lateral steering tunnel according to the embodiment of FIG. 15. [Figure 17] FIG. 16 is a cross-sectional view of a hull in a substantially vertical cross section in the vicinity of a tunnel entrance opening according to the embodiment of FIG. [Figure 18] FIG. 16 is a cross-sectional view of the hull in a substantially horizontal section at the lateral steering tunnel according to the embodiment of FIG. [Figure 19] FIG. 13 illustrates a lattice of a lateral steering tunnel according to a sixth embodiment of the present invention. [Figure 20] FIG. 20 is a cross-sectional view of the hull in a substantially horizontal section at the lateral steering tunnel according to the embodiment of FIG. 19. [Figure 21] FIG. 2 is a cross-sectional view of a hull in a substantially horizontal section at a lateral steering tunnel with an opening edge joined according to a first embodiment of said opening edge; [Figure 22] FIG. 13 is a cross-sectional view of a hull in a substantially horizontal cross section at a lateral steering tunnel with an angled opening edge according to a second embodiment of the opening edge. [Diagram 23] FIG. 13 is a cross-sectional view of a hull in a substantially horizontal cross section at a lateral steering tunnel according to a third embodiment of the opening edge, said opening edge comprising a conical flare. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] With reference to the accompanying drawings, the reference number 1 generally indicates a lateral propulsion device for a ship, the reference number 2 generally indicates the ship.

[0021] The ship 2 has a hull 21, and the hull 21 has an outer hull surface 210. During navigation, an external water flow 200 flows locally along the outer hull surface 210 in a flow direction S.

[0022] In one embodiment, the vessel 2 is equipped with a lateral propulsion device.

[0023] In general, the vessel 2 includes a forwardly projecting bulbous bow 29 configured to direct the external water flow 200 along the vessel exterior surface 210, and in particular along a flow direction S. The flow direction S is typically inclined by a flow angle in the range of 5 degrees to 60 degrees with respect to a horizontal bottom surface extending primarily along the vessel's keel.

[0024] Under conditions of forward movement and steering of the vessel at cruising speed, the external water current 200 flows at high velocity along the exterior hull surface 210 .

[0025] Sailing speed is intended as the ship's sailing speed comprised between 10 knots and 25 knots, preferably equal to about 18 knots.

[0026] A high external water flow velocity is defined as a velocity close to or greater than 4 meters per second, preferably greater than 5 meters per second, such as comprised between 7 meters per second and 10 meters per second. Conversely, a low external water flow velocity is intended as a velocity close to or less than 2.5 meters per second, such as approximately equal to 1 meter per second.

[0027] The lateral propulsion system extends laterally within the hull and preferably comprises a lateral steering tunnel 25 opening on both longitudinal sides of the hull.

[0028] In one embodiment, the lateral propulsion device comprises at least one steering propeller housed within the lateral steering tunnel 25 and configured to move water from the interior to the exterior of the lateral steering tunnel 25 through the tunnel entrance opening 28 in an active lateral propulsion device configuration.

[0029] In the inoperative configuration of the lateral thrusters, the steering propellers are stationary.

[0030] In another embodiment, the lateral propulsion device is devoid of steering propellers. In one embodiment, the lateral steering tunnel is of the anti-suction type, for example with a diameter equal to about 1.5 meters, and is configured to fluidly connect the two longitudinal sides of the vessel in order to attenuate or block the opposing water currents generated by the steering propellers of the other lateral steering tunnel.

[0031] The lateral steering tunnel 25 includes tunnel walls 27 that peripherally define the lateral steering tunnel 25 within the hull 21 .

[0032] The lateral steering tunnel 25 includes a tunnel axis X oriented to be incident on the outer hull surface 210, e.g., along which the tunnel walls 27 extend primarily. As used herein, incident refers to intersecting or oriented in an intersecting direction.

[0033] The lateral steering tunnel 25 includes an opening edge 26 that extends at least partially about a tunnel axis X and defines a tunnel entrance opening 28 that opens onto the outer hull surface 210 .

[0034] Specifically, the tunnel entrance opening 28 is disposed on a protrusion of the outer hull surface 210 between the opening edges 26 .

[0035] In one embodiment, the opening edge 26 is connected to the tunnel wall 27 with a connection radius comprised between 100 and 500 millimeters, preferably between 200 and 400 millimeters.

[0036] In one embodiment, the opening edge is located downstream of the lateral steering tunnel along the flow direction and includes a significantly flared stern portion having the purpose of promoting external water flow.

[0037] Preferably, the lateral steering tunnel 25 further comprises a second opening edge opposite the tunnel entrance opening 28, eg, opposite along the tunnel axis X, that defines a tunnel exit opening.

[0038] Along the flow direction S, the opening edge 26 is divided into a first edge portion 261 and a second edge portion 262 complementary to the first edge portion 261, both having an extension around the tunnel axis X, for example a substantially circular or elliptical or oval-shaped extension.

[0039] Along the flow direction S, the first edge portion 261 is destined to be surrounded by the outer water flow 200 first.

[0040] In other words, along the flow direction S, the external water flow 200 first encounters the first edge portion 261 and then encounters the second edge portion 262.

[0041] In other words, the first edge portion 261 extends substantially, at least partially, around the tunnel axis X according to the flow direction S towards the bow.

[0042] In other words, the opening edge 26 is composed of a first edge portion 261 and a second edge portion 262 .

[0043] Similarly, the tunnel entrance opening 28 is divided into a first half region 281 partially defined by the first edge portion 261 and a second half region 282 complementary to the first half region 281 and partially defined by the second edge portion 262.

[0044] In other words, along the flow direction S, the external water flow 200 encounters the first half-region 281 and thereafter the second half-region 282 .

[0045] In other words, the tunnel entrance opening 28 is composed of a first half region 281 and a second half region 282 .

[0046] The opening edge 26 extends along the tunnel axis X between an inner edge 265 connected to the tunnel wall 27 and an outer edge 267 connected to the outer hull surface 210 .

[0047] In one embodiment, the opening edge 26 includes a central edge 266 disposed along the tunnel axis X between an inner edge 265 and an outer edge 267 .

[0048] In one embodiment, the opening edge 26 has substantially the shape of a corner, for example a substantially right angle (FIG. 22).

[0049] In one embodiment, the aperture edge 26 flares, and preferably includes a flared portion (FIG. 23).

[0050] In one embodiment, the opening edge 26 extends between a first edge portion 273 flush with the outer hull surface 210 and a second edge portion 270 spaced apart inside the lateral steering tunnel 25 along the tunnel axis X by a height comprised between 400 and 600 millimeters from the first edge portion 273.

[0051] The lateral propulsion system comprises a grille 4 associated with a lateral steering tunnel 25 .

[0052] In one embodiment, the grating 4 is fixed to the aperture edge 26 .

[0053] In one embodiment, the grid 4 is fixed in a removable manner to the opening edge 26, for example by means of bolts and screws.

[0054] In one embodiment, the grid 4 extends over the entire tunnel entrance opening 28 .

[0055] In one embodiment, the grating 4 engages a first edge portion 261 and a second edge portion 262 .

[0056] The grating 4 includes a number of uprights 41 and a number of cross members 42 oriented to be incident on the uprights 41 .

[0057] The intersections of the cross members 42 and the upright members 41 as a whole form a lattice 4.

[0058] In one embodiment, at least some or all of the uprights 41 are oriented substantially perpendicular to the machine direction S.

[0059] In one embodiment, the lattice 4 has a thickness, i.e. the dimension of the uprights 41 and cross members 42 along the tunnel axis X, greater than 70 millimeters. Preferably, the thickness of the lattice 4 is comprised between 80 and 130 millimeters.

[0060] In one embodiment, the grid 4 cooperates with the exterior hull surface 210 to form a generally hydrodynamically shaped surface along which the exterior water flow 200 flows.

[0061] In particular, the grille 4 cooperates with the outer hull surface 210 in the second half region 282 of the tunnel entrance opening 28 .

[0062] In one embodiment, the grid 4 is positioned such that the grid surface 45 substantially abuts the outer hull surface 210 near or at the outer cross-member end 422 .

[0063] In one embodiment, the grid 4 is positioned such that the grid surface 45 substantially abuts the outer hull surface 210 at or near the second edge portion 262.

[0064] In one embodiment, the grating 4 extends over a curved grating surface 45 .

[0065] In one embodiment, the grid 4 extends over a curved grid surface 45 that is convex with respect to the lateral steering tunnel 25 .

[0066] In one embodiment, all or only some of the uprights 41 and all or only some of the cross members 42 intersect to define a number of functional through windows 40 between the uprights and cross members.

[0067] In one embodiment, for all or only some of the functional through windows 40, the upright distance d along the flow direction S between two consecutive uprights 41 that define the functional through window 40 is comprised between 150 millimeters and 250 millimeters.

[0068] In one embodiment, the upright distance d is comprised between 180 mm and 220 mm.

[0069] In one embodiment, for all or only some of the functional through windows 40, the distance between the two cross members 42 that define the functional through window 40 is comprised between 300 and 500 millimeters, for example equal to 400 millimeters.

[0070] In one embodiment, all or only a portion of the functional through window 40 has a major dimension along a direction incident on the flow direction S or substantially perpendicular to the flow direction S.

[0071] In one embodiment, all or some of the functional through windows 40 have a substantially rectangular shape with the longer side of the rectangle oriented substantially perpendicular to the flow direction S.

[0072] In one embodiment, all or only a portion of the functional through window 40 is essentially rectangular in shape, with the longer side of the rectangle being approximately equal to twice the shorter side of the rectangle.

[0073] In one embodiment, with the lateral steering tunnel 25 at least partially filled with water and the external water flow 200 flowing along the flow direction S at a high velocity, preferably greater than 4 meters per second, the lateral propulsion device is configured to keep the water within the lateral steering tunnel 25 at a low velocity along the tunnel axis X, preferably less than 2.5 meters per second.

[0074] In one embodiment, when the external water flow 200 is flowing along the flow direction S at a high velocity, preferably greater than 4 meters per second, the functional through windows 40 are configured to cooperate with each other to form a low-friction hydrodynamic surface that urges the external water flow 200 along the flow direction S.

[0075] In one embodiment, when the external water flow 200 is flowing at a high speed along the flow direction S, preferably at a speed greater than 4 meters per second, the functional through windows 40 are configured to cooperate with each other to restrict or prevent the external water flow 200 crossing the functional through windows 40 toward the inside of the lateral steering tunnel 25.

[0076] In one embodiment, when the external water flow 200 is flowing at a high speed along the flow direction S, preferably at a speed greater than 4 meters per second, the functional through window 40 is configured to keep the water at a low speed, preferably less than 2.5 meters per second, within the functional through window 40 and / or the lateral steering tunnel 25 adjacent to the functional through window 40.

[0077] In one embodiment, the tunnel entrance opening 28 may be approximated by an imaginary entrance circumference extending about the tunnel axis X on the entrance plane P, which defines an entrance area A.

[0078] In one embodiment, each functional through window 40 has a functional area Af on the grating surface 45.

[0079] In one embodiment, the functional ratio Af / A between the functional area Af and the inlet area A is comprised between 0.05% and 3%.

[0080] Preferably, the functional ratio Af / A is comprised between 1% and 2.5%, for example equal to about 1.7%.

[0081] In one embodiment, the uprights 41 have a reduced size along the machine direction S. In other words, with respect to the machine direction S, the uprights are thin.

[0082] In one embodiment, the grid 4 comprises a grid surface 45 along which the uprights 41 and cross members 42 are arranged.

[0083] The grating surface 45 is incident on the tunnel axis X.

[0084] The grating surface 45 is incident on the exterior hull surface 210 .

[0085] The grid surface 45 is an imaginary surface that is at least partially curved in space, defined by the position of the lateral steering tunnels along the hull and along the flow direction S.

[0086] In one embodiment, the grating surface 45 is substantially a grating plane 45 .

[0087] In one embodiment, the grid surface 45 is inclined with respect to the outer hull surface 210, forming a grid angle α comprised between 5 and 20 degrees, preferably between 7 and 12 degrees.

[0088] In one embodiment, the grid angle α is convex with respect to the flow direction S, i.e., faces the flow direction S.

[0089] In one embodiment, the grating surface 45 is inclined with respect to the tunnel axis X by an interior angle δ comprised between 70 and 85 degrees, preferably between 78 and 83 degrees.

[0090] Preferably, the interior angle δ is complementary to the grid angle α.

[0091] Preferably, the tunnel wall 27 is provided with a number of fastening ledges 275 which protrude into the lateral steering tunnel 25, e.g. protruding from the tunnel wall or the opening edge, which are configured to mechanically engage at least one of the uprights 41 and / or cross members 42, e.g. by bolt threads or by form or force locking.

[0092] In one embodiment, on the grid plane 45, along the flow direction S, the grid 4 comprises at least one upright 41 mechanically connected to the inner edge portion 265, at least one upright 41 mechanically connected to the central edge portion 266, and at least one upright 41 mechanically connected to the outer edge portion 267.

[0093] In one embodiment, the uprights 41 extend between a first upright end 411 and a second upright end 412 relative to the tunnel entrance opening 28 .

[0094] The grid 4 includes cross-members 42 extending on a grid surface 45, e.g., grid plane 45, between an inner cross-member end 421 and an opposite outer cross-member end 422.

[0095] Preferably, the inner cross-member end 421 is continuous with the tunnel wall 27 .

[0096] The inner cross-piece end 421 is mechanically connected to the inner edge 265 or to the tunnel wall 27 adjacent the inner edge 265 .

[0097] The outer cross-piece end 422 is mechanically connected to the outer edge 267 or to a portion of the aperture edge 26 between the inner edge 265 and the outer edge 267 .

[0098] In one embodiment, the inner cross-piece end 421 is mechanically connected to the inner edge portion 265 .

[0099] In one embodiment, the outer cross-piece end 422 is mechanically connected to the outer edge portion 267 .

[0100] In one embodiment, the inner cross-piece end 421 is mechanically connected to the first edge portion 261 of the aperture edge.

[0101] In one embodiment, the outer cross-piece end 422 is mechanically connected to the second edge portion 262 of the aperture edge.

[0102] In one embodiment, such as that of FIG. 8, all of the uprights 41 are oriented substantially perpendicular to the flow direction S.

[0103] The grid 4 comprises at least one cross member 42 extending on a grid surface 45, e.g. a grid plane 45, between an inner cross member end 421 mechanically connected to the inner edge portion 265 and an outer cross member end 422 mechanically connected to the outer edge portion 267.

[0104] In one embodiment, the grid 4 is positioned such that the outer cross-member end 422 is proximal to the outer hull surface 210 and the inner cross-member end 421 is distal to the outer hull surface 210 .

[0105] In one embodiment, the grid 4 is positioned such that the outer cross-member end 422 is in a more proximal position relative to the outer hull surface 210 relative to the position of the inner cross-member end 421 .

[0106] In one embodiment, in the first half region 281 , along the tunnel axis X, the grid 4 is lowered with respect to the outer hull surface 210 .

[0107] In one embodiment, at least one upright 41 is substantially in the shape of a polyline or a broken straight line.

[0108] Preferably, the at least one upright 41 includes at least two upright segments 417, 419 extending across two mutually distinct, incident imaginary straight lines R1, R2 extending primarily across the grating surface 45.

[0109] In one embodiment, the at least one upright 41 includes at least one upright segment 417, 419 inclined at an upright angle β1, β2 that is convex with respect to the flow direction S.

[0110] In one embodiment, the upright angles β1, β2 are less than 90°.

[0111] In one embodiment, the upright angles β1, β2 are comprised between 15 degrees and 60 degrees, for example equal to about 45 degrees.

[0112] In one embodiment, the at least one upright 41 includes at least one upright segment 418 that is substantially perpendicular with respect to the flow direction S on the grid surface 45 .

[0113] In one embodiment, all uprights 41 are substantially in the shape of a polyline or broken straight line, and each upright 41 includes a central upright segment 418 substantially perpendicular to the flow direction S on the grid surface 45 and two inclined upright segments 417, 419 arranged in succession at either end of the central upright segment 418.

[0114] In one embodiment, at least one upright 41 has a substantially curved shape.

[0115] In one embodiment, at least one upright 41 has the shape of a substantially circumferential arc.

[0116] In one embodiment, the circumferential arc is convex with respect to the flow direction S.

[0117] In one embodiment, the lattice 4 is housed within the lateral steering tunnel 25 and includes at least one cross member, as illustrated in Figure 14. Preferably, all cross members have an inner cross member end 421 and an outer cross member end 422 that are mechanically connected to the tunnel wall 27 near the inner edge 265 of the opening edge 26.

[0118] In one embodiment, as shown for example in Figures 16, 17 and 18, the grid 4 includes at least one upright, preferably all uprights, having a first upright end 411 mechanically connected to the tunnel wall 27, preferably near the inner edge 265 of the opening edge 26.

[0119] In particular, the first upright end 411 is the lower end of said at least one upright 41 .

[0120] Additionally, at least one upright, and preferably all of the uprights, have a second upright end 412 that is mechanically coupled to the tunnel wall 27 distal to the inner edge 265 .

[0121] In particular, the second upright end 412 is the upper end of said at least one upright 41 .

[0122] In one embodiment, the grating surface 45 is incident on the tunnel wall 27 and perpendicular to the tunnel axis X, as shown, for example, in FIGS.

[0123] In one embodiment, the lateral steering tunnel 25 has an entrance plane P incident on the tunnel axis X, and the tunnel entrance opening 28 has an entrance area A on the entrance plane P.

[0124] In one embodiment, the entrance plane P is perpendicular to the tunnel axis X.

[0125] In one embodiment, the entrance plane P passes substantially through the aperture edge 26 .

[0126] In one embodiment, the first edge portion 261 corresponds to a circumferential arc of an imaginary entrance circle subtended by an angle less than 180 degrees, preferably less than 150 degrees, and more preferably less than 140 degrees.

[0127] In one embodiment, the first edge portion 261 corresponds to a circumferential arc of an imaginary entrance circle subtended by an angle comprised between 100 degrees and 140 degrees, preferably between 120 degrees and 130 degrees.

[0128] In one embodiment, the flow direction S is substantially bisected by an angle that encompasses a circumferential arc corresponding to the first edge portion 261 .

[0129] In one embodiment, the ship 2 has an overall length greater than 200 m, for example equal to 250 m.

[0130] In one embodiment, the lateral steering tunnel 25 has an inner diameter between the tunnel walls 27 comprised between 2.0 meters and 2.8 meters, preferably comprised between 2.1 meters and 2.5 meters, for example 2.2 meters.

[0131] Innovatively, the lateral propulsion device that is the subject of the present invention achieves its intended purpose and overcomes the typical problems of the prior art by simplifying the hull structure, reducing the weight, and facilitating the design, installation and maintenance operations.

[0132] Advantageously, the lateral propulsion system minimizes the potentially damaging effects of hull slam while protecting the lateral steering tunnel.

[0133] Advantageously, the lateral propulsion device achieves a good compromise between structural simplicity and minimization of unwanted turbulent phenomena along the outer surface of the vessel. Advantageously, the lateral propulsion device generates low turbulence at high sailing speeds, preferably above 9 or 10 knots, where turbulent resistance has a significant impact on the efficiency of the vessel.

[0134] Advantageously, the external water flow flows along the tunnel entrance opening in a substantially constant manner along the flow direction.

[0135] Advantageously, the grid is denser with respect to grids typically used in prior art lateral propulsion devices, i.e. it has substantially double or triple the number of uprights, reducing the generation of turbulence.

[0136] Advantageously, said grid has a dimension along the tunnel axis that is thicker with respect to grids typically used in prior art lateral propulsion devices, which contributes to preventing or limiting the traversal of the functional through window.

[0137] Advantageously, the grille allows the passage of water through the tunnel entrance opening with the lateral propulsion device in operation.

[0138] Advantageously, the grid achieves a compromise between minimizing the throttling effect of the tunnel entrance opening and maximizing the effect of conveying the external water flow at high velocity along the flow direction.

[0139] Advantageously, the grid allows for a steep pressure gradient between the interior and exterior of the lateral steering tunnel due to the hull impacting with the water.

[0140] Advantageously, the uprights create reduced friction against the external water flow along the flow direction.

[0141] Advantageously, in the grid, the uprights have a reduced surface area facing the external water flow so that the external water flow encounters mainly the functional through windows and therefore slides over the water present at the functional through windows with a low coefficient of friction.

[0142] Advantageously, in high speed external water flows, said functional through window achieves the closing function of the tunnel entrance opening.

[0143] Advantageously, the grid utilizes the kinematic inertia of the external water flow to direct the water outside the lateral steering tunnel along the flow direction, minimizing or eliminating crossover at the functional through window.

[0144] Advantageously, the structural complexity of the lateral propulsion device is reduced.

[0145] Advantageously, the grid is removably connected, eliminating the need to dry-dock the vessel.

[0146] Advantageously, the grid can be removed to access the interior of the steering tunnel for inspection and maintenance work.

[0147] Advantageously, the grid is adaptable to different embodiments of the aperture edge.

[0148] Advantageously, in a lattice with uprights having a broken straight shape, the inclined upright segments encourage the external water flow from the centre of the tunnel entrance opening towards the opening edge, i.e. in a centrifugal direction with respect to the tunnel axis X. Advantageously, said inclined upright segments contribute to preventing or restricting the inflow of water into said lateral steering tunnel, i.e. encouraging the external water flow along said flow direction.

[0149] Advantageously, in an embodiment of the lattice having convex uprights in the form of a circumferential arc, the radius of curvature encourages external water flow from the centre of the tunnel entrance opening towards the opening edge, i.e. in a centrifugal direction with respect to the tunnel axis X. Advantageously, the uprights in the form of a circumferential arc prevent or limit the inflow of water into said lateral steering tunnel.

[0150] It is obvious that a person skilled in the art can make modifications to the invention described above so as to meet all unforeseen requirements within the scope of protection defined by the following claims.

[0151] For example, a person skilled in the art could make a lateral thruster that is a lattice substantially as described above, but including only uprights or only cross members, but such an equivalent solution is not preferred, since the lattice would be subject to highly undesirable vibration and resonance phenomena. [Explanation of symbols]

[0152] 1 Lateral propulsion device 2 ships 21 Hull 200 External water flow 210 Hull exterior 25 Lateral Steering Tunnel 26 Opening Edge 261 First edge part 262 Second edge part 265 Inner edge 266 Center Edge 267 Outer edge 27 Tunnel Wall 270 Second Edge Section 273 First Edge Section 275 Fixing Ledge 28 Tunnel Entrance Opening 281 First Half Region 282 Second Half Region 4 lattice 40 Functional through window 41 Upright timber 411 1st upright end 412 2nd upright end 417 Upright Segment (Slope) 418 Upright Segment (Center) 419 Upright Segment (Slope) 42 Cross member 421 Inner cross member end 422 Outside cross member end A entrance area d Upright distance P entrance plane S Flow direction X Tunnel Axis α lattice angle δ Interior angle β Upright angle

Claims

1. A lateral propulsion device (1) for a ship (2), comprising: The ship (2) comprises a hull (21) having an outer hull surface (210), along which an external water flow (200) locally flows in a flow direction (S); The lateral propulsion device is a lateral steering tunnel (25) including tunnel walls (27) extending along a tunnel axis (X) oriented incident on said outer hull surface (210) and an opening edge (26) extending at least partially around said tunnel axis (X) and defining a tunnel entrance opening (28) opening onto said outer hull surface (210), the opening edge (26) extends along the tunnel axis (X) between an inner edge (265) incident on the tunnel axis (X) and connected to the tunnel wall (27) and an outer edge (267) incident on the tunnel axis (X) and connected to the outer hull surface (210); a lattice (4) associated with said lateral steering tunnel (25), said lattice (4) including a plurality of cross members (42) and / or upright members (41) intersecting with one another and extending mainly over said tunnel axis (X) and a lattice surface (45) intersecting with said outer hull surface (210), The lattice (4) is an inner cross-piece end (421) mechanically connected to said inner edge (265) or to a part of said tunnel wall (27) proximal to said inner edge (265); an outer cross-piece end (422) mechanically connected to said outer edge (267) or to a portion of said opening edge (26) axially sandwiched between said inner edge (265) and said outer edge (267); and at least one cross member (42) extending across said lattice surface (45) between said cross members (42). A lateral propulsion device comprising:

2. 2. The lateral propulsion device of claim 1, The grating surface (45) is substantially a grating plane (45). A lateral propulsion device comprising:

3. 3. A lateral propulsion device according to claim 1 or 2, The lattice (4) includes at least one cross member (42) extending across the lattice surface (45) between an inner cross member end (421) mechanically connected to the inner edge portion (265) and an outer cross member end (422) mechanically connected to the outer edge portion (267). A lateral propulsion device comprising:

4. A lateral propulsion device according to any one of claims 1 to 3, All said uprights (41) are oriented substantially perpendicular to said flow direction (S). A lateral propulsion device comprising:

5. A lateral propulsion device according to any one of claims 1 to 3, At least one upright (41) is substantially in the form of a polyline or broken straight line and includes at least two upright segments (417, 419) extending across two mutually distinct, incident imaginary straight lines (R1, R2) that extend primarily across the lattice surface (45). A lateral propulsion device comprising:

6. 6. The lateral propulsion device of claim 5, The at least one upright (41) includes at least one upright segment (418) that is substantially perpendicular to the flow direction (S) across the grid surface (45). A lateral propulsion device comprising:

7. A lateral propulsion device according to any one of claims 1 to 3, At least one upright (41) is substantially curved. A lateral propulsion device comprising:

8. A lateral propulsion device according to any one of claims 1 to 7, Along the flow direction (S), the opening edge (26) is divided into a first edge portion (261), intended to be initially surrounded by the external water flow (200), and a second edge portion (262), complementary to the first edge portion (261); the inner cross-member end (421) is mechanically connected to the first edge portion (261); The outer cross member end (422) is mechanically connected to the second edge portion (262). A lateral propulsion device comprising:

9. 9. The lateral propulsion device of claim 8, In the second half region (282), the grid (4) cooperates with the outer hull surface (210) to form a surface having an overall hydrodynamic shape along which the external water flow (200) flows. A lateral propulsion device comprising:

10. A lateral propulsion device according to any one of claims 1 to 9, The grid (4) includes at least one cross member (42) extending across a curved grid surface (45) and having an outer cross member end (422) substantially tangent to the outer hull surface (210). A lateral propulsion device comprising:

11. A lateral propulsion device (1) for a ship (2), comprising: The ship (2) comprises a hull (21) having an outer hull surface (210), along which an external water flow (200) locally flows in a flow direction (S); The lateral propulsion device is a lateral steering tunnel (25) including tunnel walls (27) extending along a tunnel axis (X) oriented incident on said outer hull surface (210) and an opening edge (26) extending at least partially around said tunnel axis (X) and defining a tunnel entrance opening (28) opening onto said outer hull surface (210), Along the flow direction (S), the opening edge (26) is divided into a first edge portion (261), intended to be initially surrounded by the external water flow (200), and a second edge portion (262), complementary to the first edge portion (261); a lattice (4) associated with said lateral steering tunnel (25), said lattice (4) comprising a plurality of cross members (42) and upright members (41) intersecting with one another and extending mainly across said tunnel axis (X) and a lattice surface (45) intersecting with said outer hull surface (210); a tunnel entrance opening (28) divided into a first half-region (281) partially defined by the first edge portion (261) and a second half-region (282) complementary to the first half-region (281) and partially defined by the second edge portion (262); In the first half-region (281), the grid (4) is lowered along the tunnel axis (X) with respect to the outer hull surface (210) towards the inside of the volume of the ship (2) defined by the outer hull surface (210). A lateral propulsion device comprising:

12. A lateral propulsion device according to any one of claims 1 to 11, The grid (4) is mechanically connected to the tunnel wall (27) in a removable manner while the hull (21) is submerged in water, for example by means of bolt screws connected to fixing ledges (275) protruding from the tunnel wall (27) and / or the opening edge (26). A lateral propulsion device comprising:

13. A lateral propulsion device according to any one of claims 1 to 12, all or some of the uprights (41) and all or some of the cross members (42) define a plurality of functional through windows 40 between the uprights and the cross members; The grid (4) is configured to prevent or restrict the external water flow (200) from passing through the functional through window (40) when the external water flow (200) is flowing at high speed along the flow direction (S), preferably at a speed of more than 4 meters per second. A lateral propulsion device comprising:

14. 14. The lateral propulsion device of claim 13, The functional through window (40) has a major dimension in a direction incident on or substantially perpendicular to the flow direction (S). A lateral propulsion device comprising:

15. 15. The lateral propulsion device of claim 14, The upright distance (d) along the flow direction (S) between two consecutive uprights (41) defining a functional through window (40) is between 150 and 250 mm, preferably between 180 and 220 mm. A lateral propulsion device comprising:

16. 16. A lateral propulsion device according to any one of claims 13 to 15, The functional through-window (40) is configured to keep water at a low velocity, preferably less than 2.5 meters per second, at the functional through-window (40) and / or inside the lateral steering tunnel (25) adjacent to the functional through-window (40). A lateral propulsion device comprising:

17. 17. A lateral propulsion device according to any one of claims 1 to 16, In a non-operated configuration, with the lateral steering tunnel (25) at least partially filled with water and with the external water flow (200) flowing at a high speed along the flow direction (S), preferably at a speed of more than 4 meters per second, the functional through-windows (40) are configured to cooperate with one another to keep the water in the lateral steering tunnel (25) at a low speed along the tunnel axis (X), preferably at a speed of less than 2.5 meters per second. A lateral propulsion device comprising:

18. A lateral propulsion device (1) for a ship (2), comprising: The ship (2) comprises a hull (21) having an outer hull surface (210), along which an external water flow (200) locally flows in a flow direction (S); The lateral propulsion device is a lateral steering tunnel (25) including tunnel walls (27) extending along a tunnel axis (X) oriented incident on said outer hull surface (210) and an opening edge (26) extending at least partially around said tunnel axis (X) and defining a tunnel entrance opening (28) opening onto said outer hull surface (210), the opening edge (26) forms a substantially straight corner or includes a flared expansion between the outer hull surface (210) and the tunnel wall (27); said opening edge (26) extends between a first edge portion (273) flush with said outer hull surface (210) and a second edge portion (270) spaced apart from said first edge portion (273) by an amount between 400 and 600 millimeters along said tunnel axis (X), inside said lateral steering tunnel (25); a lattice (4) associated with said lateral steering tunnel (25), said lattice (4) including a plurality of cross members (42) and / or upright members (41) intersecting with one another and extending mainly over said tunnel axis (X) and a lattice surface (45) intersecting with said outer hull surface (210), The lattice (4) is an inner cross-piece end (421) mechanically connected to said second edge (270) or to a portion of said tunnel wall (27) proximate said second edge (270); an outer cross-piece end (422) mechanically connected to said first edge portion (273) or to a portion of said opening edge (26) axially sandwiched between said first edge portion (273) and said second edge portion (270); and at least one cross member (42) extending across said lattice surface (45) between said cross members (42). A lateral propulsion device comprising:

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