[0001] The present invention relates to a transverse propulsion device of a ship.
[0002] Preferably, the present invention is aimed at large ships, such as container ships
or cruise ships.
[0003] In the context of ship handling, it is known that, in order to carry out berthing
and unberthing maneuvers in confined spaces and at low speeds, special transverse
propulsion devices provided with maneuvering propellers with a rotation axis oriented
transversely to the vertical longitudinal plane or diametrical plane of the vessel
are indispensable.
[0004] In order to protect the transverse propulsion devices from possible shocks, it is
known to affix gratings to the inlet opening of the maneuvering tunnel transverse
to the hull of the ship, in which the maneuvering propellers are housed.
[0005] Additionally, in order to reduce turbulence phenomena during navigation, it is known
to include special closing devices provided with movable doors, typically placed at
the openings of the transverse maneuvering tunnels. The doors are movable between
an open position, in which they allow a water flow inside the maneuvering tunnel,
and a closed position, in which they completely close the tunnel inlet opening and
substantially reconstruct the outer surface of the hull.
[0007] Such transverse maneuvering tunnel closing devices have many critical aspects known
to designers in the naval field.
[0008] The main problems include the design of the hydrodynamic shape of the doors, aimed
at minimizing, during cruising, turbulence due to shape discontinuities between the
doors and the outer surface of the hull, and at the same time aimed at minimizing
bulk in the open position, i.e., during the operation of the transverse propulsion
devices.
[0009] At the same time, the closing devices of the transverse maneuvering tunnels have
high structural complexity and contribute to increasing the overall weight of the
ship.
[0010] Additionally, the transverse maneuvering tunnel closing devices must be designed
to minimize the potentially damaging effects of the slamming phenomena of the ship's
hull (generally the bow) abruptly plunging into water, e.g., due to the wave motion
of the water. Especially at high speeds, such slamming phenomena generate high pressure
gradients at the transverse maneuvering tunnels, and can cause damage to the ship's
plating and connections, or impair the operation of the doors and the transverse propulsion
device.
[0011] Such critical aspects and related problems push designers towards conflicting technical
solutions, on the one hand towards the complete closure of the transverse maneuvering
tunnel inlet opening to better reconstruct the hydrodynamic shape of the hull, and
on the other hand towards the complete opening of the tunnel inlet openings to simplify
and lighten the hull and eliminate any sudden pressure gradients between the inside
and outside of the maneuvering tunnel.
[0012] The object of the present invention is to make a transverse propulsion device which
makes it possible to overcome the drawbacks highlighted for the solutions of the prior
art.
[0013] An object of the present invention is to provide a transverse propulsion device which
achieves a compromise between generating low drag and turbulence during cruising,
while at least partially preserving the mainly laminar water flows lapping the ship's
hull externally near the transverse maneuvering tunnel inlet openings, and at the
same time maximizes the overall weight reduction and reduction in structural complexity
of the ship's hull.
[0014] Specifically, one of the objects of the present invention is to make a structurally
simple transverse propulsion device having an extremely reduced number of components.
[0015] Yet another object of the present invention is to provide a transverse propulsion
device with extremely limited weight.
[0016] An even further object is to provide a transverse propulsion device which can simplify
installation and maintenance operations.
[0017] Still further, an object of the present invention is to eliminate or dampen the formation
of high pressure gradients between the inside and outside of the transverse maneuvering
tunnel, typically due to the slamming phenomena of the ship's hull.
[0018] These and other objects are achieved by means of a transverse propulsion device of
a ship according to claim 1. The dependent claims show preferred embodiments involving
a series of advantageous technical effects.
[0019] The features and advantages of the invention will be evident from the description
below, from its preferred embodiment examples and the accompanying figures, in which:
- figure 1 shows a detail of a hull of a ship having a plurality of maneuvering tunnels
and a closing device associated with each maneuvering tunnel, according to an embodiment
of the invention;
- figure 2 illustrates a forward part of a ship, having a plurality of maneuvering tunnels
made in the hull, and a closing device associated with a maneuvering tunnel, according
to an embodiment of the invention;
- figure 3 depicts a cross-sectional view of the ship's hull at the transverse maneuvering
tunnel, according to an embodiment of the invention;
- figure 4 depicts a frontal view of a pair of grids for two transverse maneuvering
tunnels, aligned along the outer flow direction, according to an embodiment of the
invention;
- figure 5 shows a grid of a transverse maneuvering tunnel, according to a first embodiment
of the invention;
- figure 6 depicts a grid of a transverse maneuvering tunnel, according to a second
embodiment of the invention;
- figure 7 illustrates a grid of a transverse maneuvering tunnel, according to a third
embodiment of the invention;
- figure 8 depicts a perspective view of the grid of figure 5;
- figure 9 shows a sectional view of the ship's hull on a substantially vertical cross-sectional
plane of the ship, near the tunnel inlet opening, according to the embodiment of figure
5;
- figure 10 depicts a sectional view of the ship's hull on a substantially horizontal
cross-sectional plane, at the transverse maneuvering tunnel, according to the embodiment
of figure 5;
- the figure illustrates a perspective view of the grid of figure 6;
- figure 12 depicts a perspective view of the grid of figure 7;
- figure 13 shows a grid of a transverse maneuvering tunnel, according to a fourth embodiment
of the invention;
- figure 14 depicts a sectional view of the ship's hull on a substantially horizontal
cross-sectional plane, at the transverse maneuvering tunnel, according to the embodiment
of figure 13;
- figure 15 illustrates a perspective view of the grid of a transverse maneuvering tunnel,
according to a fifth embodiment of the invention;
- figure 16 shows a grid of a transverse maneuvering tunnel, according to the embodiment
of figure 15;
- figure 17 depicts a sectional view of the ship's hull on a substantially vertical
cross-sectional plane of the ship, near the tunnel inlet opening, according to the
embodiment of figure 15;
- figure 18 depicts a sectional view of the ship's hull on a substantially horizontal
cross-sectional plane, at the transverse maneuvering tunnel, according to the embodiment
of figure 15;
- figure 19 shows a grid of a transverse maneuvering tunnel, according to the sixth
embodiment of the invention;
- figure 20 depicts a sectional view of the ship's hull on a substantially horizontal
cross-sectional plane, at the transverse maneuvering tunnel, according to the embodiment
of figure 19;
- figure 21 depicts a sectional view of the ship's hull on a substantially horizontal
cross-sectional plane, at the transverse maneuvering tunnel, according to a first
embodiment the opening edges, with the opening edges joined;
- figure 22 depicts a sectional view of the ship's hull on a substantially horizontal
sectional plane, at the transverse maneuvering tunnel, according to a second embodiment
of the opening edges, with angled opening edges;
- figure 23 depicts a sectional view of the ship's hull on a substantially horizontal
sectional plane, at the transverse maneuvering tunnel, according to a third embodiment
of the opening edges, with the opening edges comprising a countersink.
[0020] With reference to the attached figures, the reference number 1 indicates a transverse
propulsion device as a whole. The reference number 2 indicates a ship as a whole.
[0021] The ship 2 comprises a hull 21, which comprises an outer hull surface 210. During
cruising, an external water flow 200 flows locally along the outer hull surface 210,
along a flow direction S.
[0022] In an embodiment, the ship 2 comprises the transverse propulsion device.
[0023] Generally, the ship 2 comprises a bulbous bow 29 projecting in front, configured
to direct the external water flow 200 along the outer hull surface 210, in particular
along the flow direction S. The flow direction S is typically inclined with respect
to a horizontal bottom plane extending mainly along the keel of the ship by a flow
angle comprised between 5 degrees and 60 degrees.
[0024] Under conditions of the ship's forward motion and navigation at cruising speed, the
external water flow 200 flows along the outer hull surface 210 at high speeds.
[0025] Cruising speed is intended as ship navigation speeds comprised between 10 knots and
25 knots, preferably equal to around 18 knots.
[0026] High external water flow speeds are defined as speeds close to or greater than 4
meters per second, preferably greater than 5 meters per second, e.g., comprised between
7 and 10 meters per second. Conversely, low external water flow speeds are intended
as speeds close to or below 2.5 meters per second, e.g., about equal to 1 meter per
second.
[0027] The transverse propulsion device comprises a transverse maneuvering tunnel 25 extending
transversely in the hull of the ship, preferably open on both longitudinal sides of
the ship.
[0028] In an embodiment, the transverse propulsion device comprises at least one maneuvering
propeller housed in the transverse maneuvering tunnel 25 and configured to move water
through the tunnel inlet opening 28, from the inside to the outside of the transverse
maneuvering tunnel 25, in an operating transverse propulsion device configuration.
[0029] In an inactive configuration of the transverse propulsion device, the maneuvering
propeller is stationary.
[0030] In a different embodiment, the transverse propulsion device lacks a maneuvering propeller.
In an embodiment, the transverse maneuvering tunnel is of the anti-suction type, e.g.,
with a diameter equal to approximately 1.5 meters, configured to fluidically connect
the two longitudinal sides of the ship in order to dampen or eliminate opposite water
flows generated by the maneuvering propellers of other transverse maneuvering tunnels.
[0031] The transverse maneuvering tunnel 25 comprises tunnel walls 27 which peripherally
delimit the transverse maneuvering tunnel 25 inside the hull 21.
[0032] The transverse maneuvering tunnel 25 comprises a tunnel axis X oriented incidentally
to the outer hull surface 210, e.g., along which the tunnel walls 27 mainly extend.
[0033] The transverse maneuvering tunnel 25 comprises opening edges 26 extending at least
partially about the tunnel axis X and delimiting a tunnel inlet opening 28, open on
the outer hull surface 210.
[0034] Specifically, the tunnel inlet opening 28 is placed on the projection of the outer
hull surface 210 between the opening edges 26.
[0035] In an embodiment, the opening edges 26 are connected to the tunnel walls 27 with
a connecting radius comprised between 100 and 500 millimeters, preferably comprised
between 200 and 400 millimeters.
[0036] In an embodiment, the opening edges comprise a markedly flared aft section, located
downstream of the transverse maneuvering tunnel, along the flow direction, having
the purpose of facilitating the external water flow.
[0037] Preferably, the transverse maneuvering tunnel 25 further comprises second opening
edges delimiting a tunnel exit opening opposite the tunnel inlet opening 28, for example
opposite along the tunnel axis X.
[0038] Along the flow direction S, the opening edges 26 are divided into a first edge portion
261 and a second edge portion 262 complementary to the first edge portion 261, both
having extension around the tunnel axis X, e.g., a substantially circular or oval
or elliptical extension.
[0039] Along the flow direction S, the first edge portion 261 is destined to be lapped by
the external water flow 200 first.
[0040] In other words, along the flow direction S, the external water flow 200 initially
encounters the first edge portion 261 and subsequently the second edge portion 262.
[0041] In still other words, the first edge portion 261 substantially, at least partially,
towards the bow of the ship, extending around the tunnel axis X according to the flow
direction S.
[0042] In still other words, the opening edges 26 consist of the first edge portion 261
and the second edge portion 262.
[0043] Similarly, the tunnel inlet opening 28 is divided into a first half area 281 partially
delimited by the first edge portion 261, and a second half area 282 complementary
to the first half area 281 and partially delimited by the second edge portion 262.
[0044] In other words, along the flow direction S, the external water flow 200 encounters
the first half area 281 and then the second half area 282.
[0045] In still other words, the tunnel inlet opening 28 consists of the first half area
281 and the second half area 282.
[0046] The opening edges 26 extend along the tunnel axis X between an inner edge section
265 connected to the tunnel walls 27 and an outer edge section 267 connected to the
outer hull surface 210.
[0047] In an embodiment, the opening edges 26 comprise a central edge portion 266 comprised
along the tunnel axis X between the inner edge section 265 and the outer edge section
267.
[0048] In an embodiment, the opening edges 26 substantially have the shape of a corner,
e.g., substantially a right angle (figure 22).
[0049] In an embodiment, the opening edges 26 are flared, preferably they comprise a flared
section (figure 23) .
[0050] In an embodiment, the opening edges 26 extend between a first edge section 273 flush
with the outer hull surface 210, and a second edge section 270 inside the transverse
maneuvering tunnel 25 and spaced along the tunnel axis X by a height comprised between
400 and 600 millimeters from the first edge section 273.
[0051] The transverse propulsion device comprises a grid 4 associated with the transverse
maneuvering tunnel 25.
[0052] In an embodiment, the grid 4 is fixed to the opening edges 26.
[0053] In an embodiment, the grid 4 is fixed to the opening edges 26 in a removable manner,
e.g., by means of bolted screws.
[0054] In an embodiment, the grid 4 extends with respect to the entire tunnel inlet opening
28.
[0055] In an embodiment, the grid 4 engages the first edge portion 261 and the second edge
portion 262.
[0056] The grid 4 comprises a plurality of uprights 41 and a plurality of crosspieces 42
oriented incidentally to the uprights 41.
[0057] The intersection of the crosspieces 42 and the uprights 31 makes the grid 4 as a
whole.
[0058] In an embodiment, at least some or all of the uprights 41 are oriented substantially
orthogonal to the flow direction S.
[0059] In an embodiment, the grid 4 has a thickness, i.e., dimension of the uprights 41
and the crosspieces 42 along the tunnel axis X, greater than 70 millimeters. Preferably,
the thickness of the grid 4 is comprised between 80 and 130 millimeters.
[0060] In an embodiment, the grid 4 cooperates with the outer hull surface 210 to create
as a whole a hydrodynamically-shaped surface along which the external water flow 200
flows.
[0061] In particular, the grid 4 cooperates with the outer hull surface 210 in the second
half area 282 of the inlet opening 28.
[0062] In an embodiment, the grid 4 is positioned so that the grid surface 45 is substantially
tangent to the outer hull surface 210 near or at the outer crosspiece end 422.
[0063] In an embodiment, the grid 4 is positioned so that the grid surface 45 is substantially
tangent to the outer hull surface 210 at or near the second edge portion 262.
[0064] In an embodiment, the grid 4 extends on a curved grid surface 45.
[0065] In an embodiment, the grid 4 extends on a curved grid surface 45 which is convex
with respect to the transverse maneuvering tunnel 25.
[0066] In an embodiment, all or only some uprights 41 and all or only some crosspieces 42
intersect and delimit a plurality of functional through windows 40 therebetween.
[0067] In an embodiment, for all or only some functional through windows 40, the upright
distance D along the flow direction S between two consecutive uprights 41 delimiting
a functional through window 40 is comprised between 150 and 250 millimeters.
[0068] In an embodiment, the upright distance D is comprised between 180 and 220 millimeters.
[0069] In an embodiment, for all or only some functional through windows 40, the distance
between two crosspieces 42 delimiting a functional through window 40 is comprised
between 300 and 500 millimeters, e.g., equal to 400 millimeters.
[0070] In an embodiment, all or only some of the functional through windows 40 have a main
dimension along a direction incident upon or substantially transverse to the flow
direction S.
[0071] In an embodiment, all or only some of the functional through windows 40 have a substantially
rectangular shape, with the longer side oriented in a direction substantially transverse
to the flow direction S.
[0072] In an embodiment, all or only some of the functional through windows 40 are essentially
rectangular in shape, with the longer side of the rectangle being equal to approximately
twice the shorter side of the rectangle.
[0073] In an embodiment, with the transverse maneuvering tunnel 25 at least partially filled
with water and external water flow 200 flowing along the flow direction S at high
speeds, preferably speeds greater than 4 meters per second, the transverse propulsion
device is configured so as to keep the water inside the transverse maneuvering tunnel
25 at low speeds along the tunnel axis X, preferably speeds less than 2.5 meters per
second.
[0074] In an embodiment, with external water flow 200 flowing along the flow direction S
at high speeds, preferably speeds greater than 4 meters per second, the functional
through windows 40 are configured to cooperate with each other and create a low-friction
hydrodynamic surface which favours the external water flow 200 along the flow direction
S.
[0075] In an embodiment, with external water flow 200 flowing along the flow direction S
at high speeds, preferably speeds greater than 4 meters per second, the functional
through windows 40 are configured to cooperate with each other and limit or prevent
the external water flow 200 crossing the functional through windows 40, towards the
inside of the transverse maneuvering tunnel 25.
[0076] In an embodiment, with external water flow 200 flowing along the flow direction S
at high speeds, preferably speeds greater than 4 meters per second, the functional
through windows 40 are configured to retain water at low speeds, preferably speeds
less than 2.5 meters per second, at said functional through windows 40 and/or inside
the transverse maneuvering tunnel 25 near said functional through windows 40.
[0077] In an embodiment, the tunnel inlet opening 28 can be approximated to an imaginary
inlet circumference extending around the tunnel axis X on the inlet plane P, which
delimits the inlet area A.
[0078] In an embodiment, each functional through window 40 has a functional area Af on the
grid surface 45.
[0079] In an 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%, e.g., it
is equal to about 1.7%.
[0081] In an embodiment, the uprights 41 have a reduced size along the flow direction S.
In other words, with respect to the flow direction S, the uprights are thin.
[0082] In an embodiment, the grid 4 comprises a grid surface 45, along which the uprights
41 and the crosspieces 42 are arranged.
[0083] The grid surface 45 is incident to the tunnel axis X.
[0084] The grid surface 45 is incident to the outer hull surface 210.
[0085] The grid surface 45 is an imaginary surface which is at least partially curved in
space, identified by the position of the transverse maneuvering tunnel along the hull
and along the flow direction S.
[0086] In an embodiment, the grid surface 45 is substantially a grid plane 45.
[0087] In an 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
comprised between 7 and 12 degrees.
[0088] In an embodiment, the grid angle α is convex with respect to the flow direction S,
i.e., it faces the flow direction S.
[0089] In an embodiment, the grid surface 45 is inclined with respect to the tunnel axis
X by an internal angle δ comprised between 70 and 85 degrees, preferably between 78
and 83.
[0090] Preferably, the internal angle δ is complementary to the grid angle α.
[0091] Preferably, the tunnel walls 27 comprise a plurality of fixing ledges 275 protruding
into the transverse maneuvering tunnel 25, for example protruding from the tunnel
walls or opening edges, configured to mechanically engage at least one upright 41
and/or crosspiece 42, for example by bolted screws or by means of a shape coupling
or force coupling.
[0092] In an embodiment, on the grid plane 45 and along the flow direction S, the grid 4
comprises at least one upright 41 mechanically connected to the inner edge section
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 section 267.
[0093] In an embodiment, the uprights 41 extend with respect to the tunnel inlet opening
28 between a first upright end 411 and a second upright end 412.
[0094] The grid 4 comprises a crosspiece 42 extending on the grid surface 45, for example
a grid plane 45, between an inner crosspiece end 421 and an opposite outer crosspiece
end 422.
[0095] Preferably, the inner crosspiece end 421 is consecutive to the tunnel walls 27.
[0096] The inner crosspiece end 421 is mechanically connected to the inner edge section
265 or to the tunnel walls 27 near the inner edge section 265.
[0097] The outer crosspiece end 422 is mechanically connected to the outer edge section
267 or to a portion of the opening edges 26 between the inner edge section 265 and
the outer edge section 267.
[0098] In an embodiment, the inner crosspiece end 421 is mechanically connected to the inner
edge section 265.
[0099] In an embodiment, the outer crosspiece end 422 is mechanically connected to the outer
edge section 267.
[0100] In an embodiment, the inner crosspiece end 421 is mechanically connected to the first
edge portion 261 of the opening edges.
[0101] In an embodiment, the outer crosspiece end 422 is mechanically connected to the second
edge portion 262 of the opening edges.
[0102] In an embodiment, e.g., the embodiment of figure 8, all the uprights 41 are positioned
substantially orthogonal to the flow direction S.
[0103] The grid 4 comprises at least one crosspiece 42 extending on the grid surface 45,
for example a grid plane 45, between an inner crosspiece end 421 mechanically connected
to the inner edge section 265, and an outer crosspiece end 422 mechanically connected
to the outer edge section 267.
[0104] In an embodiment, the grid 4 is positioned so that the outer crosspiece end 422 is
in a position proximal to the outer hull surface 210 and the inner crosspiece end
421 is in a position distal to the outer hull surface 210.
[0105] In an embodiment, the grid 4 is positioned so that the outer crosspiece end 422 is
in a more proximal position to the outer hull surface 210 with respect to the position
of the inner crosspiece end 421.
[0106] In an embodiment, in the first half area 281 and along the tunnel axis X, the grid
4 is lowered with respect to the outer hull surface 210.
[0107] In an embodiment, at least one upright 41 is substantially in the shape of a polyline
or broken straight line.
[0108] Preferably said at least one upright 41 comprises at least two upright segments 417,
419 mainly extending over two mutually distinct, incident imaginary straight lines
R1, R2 mainly extending over the grid surface 45.
[0109] In an embodiment, said at least one upright 41 comprises at least one upright segment
417, 419 inclined by an upright angle β1, β2 which is convex with respect to the flow
direction S.
[0110] In an embodiment, said upright angle β1, β2 is less than 90°.
[0111] In an embodiment, said upright angle β1, β2 is comprised between 15 and 60 degrees,
e.g., it is equal to about 45 degrees.
[0112] In an embodiment, said at least one upright 41 comprises at least one upright segment
418 substantially orthogonally with respect to the flow direction S on the grid surface
45.
[0113] In an embodiment, all of the uprights 41 are substantially in the shape of a polyline
or broken straight lines, in which each upright 41 comprises a central upright segment
418 substantially orthogonal to the flow direction S on the grid surface 45, and two
inclined upright segments 417, 419, which are consecutive and arranged at the ends
of the central upright segment 418.
[0114] In an embodiment, at least one upright 41 has a substantially curved shape.
[0115] In an embodiment, at least one upright 41 has a substantially circumferential arc
shape.
[0116] In an embodiment, said circumferential arc is convex with respect to the flow direction
S.
[0117] In an embodiment, as for example shown by way of example in figure 14, the grid 4
is housed in the transverse maneuvering tunnel 25 and comprises at least one crosspiece,
preferably all the crosspieces, having inner crosspiece ends 421 and outer crosspiece
ends 422 mechanically connected to the tunnel walls 27, near the inner edge section
265 of the opening edges 26.
[0118] In an embodiment, as for example shown in figures 16, 17 and 18, the grid 4 comprises
at least one upright, preferably all the uprights, having the first upright end 411
mechanically connected to the tunnel walls 27, preferably near the inner edge section
265 of the opening edges 26.
[0119] In particular, the first upright end 411 is the lower end of said at least one upright
41.
[0120] In addition, at least one upright, preferably all the uprights, have second upright
end 412 mechanically connected to the tunnel walls 27 in a distal position of the
inner edge section 265.
[0121] In particular, the second upright end 412 is the upper end of said at least one upright
41.
[0122] In an embodiment, as for example shown in figures 16, 17 and 18, the grid 4 surface
45 is incident to the tunnel walls 27 and transverse to the tunnel axis X.
[0123] In an embodiment, the transverse maneuvering tunnel 25 comprises an inlet plane P
incident to the tunnel axis X, and the tunnel inlet opening 28 has an inlet area A
on the inlet plane P.
[0124] In an embodiment, the inlet plane P is transverse to the tunnel axis X.
[0125] In an embodiment, the inlet plane P is essentially passing through the opening edges
26.
[0126] In an embodiment, the first edge portion 261 corresponds to a circumferential arc
of the imaginary inlet circle subtended by an angle less than 180 degrees, preferably
less than 150 degrees, even more preferably less than 140 degrees.
[0127] In an embodiment, the first edge portion 261 corresponds to a circumferential arc
of the imaginary inlet circle subtended by an angle comprised between 100 and 140
degrees, preferably comprised between 120 and 130 degrees.
[0128] In an embodiment, the flow direction S is essentially secant to the angle subtending
the circumferential arc corresponding to the first edge portion 261.
[0129] In an embodiment, the ship 2 has an overall length greater than 200 meters, e.g.,
equal to 250 meters.
[0130] In an embodiment, the transverse maneuvering tunnel 25 has an internal diameter between
the tunnel walls 27 comprised between 2.0 meters and 2.8 meters, preferably comprised
between 2.1 and 2.5 meters, e.g., 2.2 meters.
[0131] Innovatively, the transverse propulsion device which is the subject of the present
invention fulfils 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 transverse propulsion device minimizes the potentially damaging
effects of hull slamming, protecting the transverse maneuvering tunnel.
[0133] Advantageously, the propulsion device achieves a high compromise between structural
simplicity and minimization of unwanted turbulence phenomena along the outer hull
surface. Advantageously, the transverse propulsion device generates low turbulence
at high cruising speeds, preferably at cruising speeds equal to or greater than 9
or 10 knots, at which turbulence resistance significantly impacts the efficiency of
the ship.
[0134] Advantageously, the external water flow flows along the tunnel inlet opening in an
essentially constant manner along the flow direction.
[0135] Advantageously, the grid is denser, i.e., it has substantially doubled or tripled
the number of uprights, with respect to the grids typically used in the transverse
propulsion devices of the prior art, reducing the generation of turbulence.
[0136] Advantageously, the grid has a dimension along the tunnel axis which is thicker with
respect to the grids typically used in the transverse propulsion devices of the prior
art. This contributes to preventing or limiting the crossing of the functional through
windows.
[0137] Advantageously, the grid allows the passage of water through the tunnel inlet opening,
with an operating transverse propulsion device.
[0138] Advantageously, the grid achieves a compromise between minimizing the throttling
effect of the tunnel inlet opening and maximizing the effect of conveying the external
water flow at high speeds along the flow direction.
[0139] Advantageously, the grid allows for sudden pressure gradients between the inside
and outside of the transverse maneuvering tunnel due to the hull slamming with water.
[0140] Advantageously, the uprights generate a reduced friction against the external water
flow along the flow direction.
[0141] Advantageously, at the grid, the external water flow mainly encounters the functional
through windows, as the uprights have a reduced surface area facing the external water
flow, thus the external water flow slides with a low friction coefficient over the
water present in the functional through windows.
[0142] Advantageously, with external water flow at high speeds, the functional through windows
achieve the closing function of the tunnel inlet opening.
[0143] Advantageously, the grid exploits the kinematic inertia of the external water flow
to conduct the water outside the transverse maneuvering tunnel, along the flow direction,
minimizing or eliminating the crossings in the functional through windows.
[0144] Advantageously, the structural complexity of the transverse propulsion devices is
reduced.
[0145] Advantageously, the grid is connected in a removable manner, obviating the need to
dry-dock the ship.
[0146] Advantageously, the grid can be removed to access the inside of the maneuvering tunnel
for inspection and maintenance operations.
[0147] Advantageously, the grid is adaptable to different embodiments of the opening edges.
[0148] Advantageously, the grid with uprights having straight broken shape, the inclined
upright segment favours the external water flow from the center of the tunnel inlet
opening towards the opening edges, i.e., in a centrifugal direction with respect to
the tunnel axis X. Advantageously, the inclined upright segment contributes to preventing
or limiting the inlet of water inside the transverse maneuvering tunnel, i.e., favouring
the flow thereof along the flow direction.
[0149] Advantageously, in the grid embodiment with convex uprights in the shape of a circumferential
arc, the radius of curvature favours the external water flow from the center of the
tunnel inlet opening towards the opening edges, i.e., in a centrifugal direction with
respect to the tunnel axis X. Advantageously, the uprights in the shape of a circumferential
arc contribute to preventing or limiting the inlet of water inside the transverse
maneuvering tunnel.
[0150] It is clear that a person skilled in the art may make modifications to the invention
described above so as to satisfy contingent requirements, all contained within the
scope of protection as defined by the following claims.
[0151] For example, a person skilled in the art could make a transverse propulsion device
comprising a grid substantially as described above but comprising only uprights or
only crosspieces. Such an equivalent solution is, however, a pejorative solution,
as the grid would be subject to highly undesirable vibrational and resonance phenomena.
LIST OF REFERENCE NUMBERS
[0152]
1 Transverse propulsion device
2 Ship
21 hull
200 external water flow
210 outer hull surface
25 transverse maneuvering tunnel
26 opening edges
261 first edge portion
262 second edge portion
265 inner edge section
266 central edge section
267 outer edge section
27 tunnel walls
270 second edge section
273 first edge section
275 fixing ledges
28 tunnel inlet opening
281 first half area
282 second half area
3 -
4 grid
40 functional through window
41 uprights
411 first upright end
412 second upright end
417 upright segment (inclined)
418 upright segment (central)
419 upright segment (inclined)
42 crosspieces
421 inner crosspiece end
422 outer crosspiece end
A inlet area
D upright distance
P inlet plane
S flow direction
X tunnel axis
α grid angle
δ internal angle
β upright angle
1. A ship transverse propulsion device (1), wherein the ship (2) comprises a hull (21)
which comprises an outer hull surface (210), along which an external water flow (200)
is intended to flow locally along a flow direction (S); wherein the transverse propulsion
device comprises:
- a transverse maneuvering tunnel (25) comprising tunnel walls (27) extending along
a tunnel axis (X) oriented incidentally to the outer hull surface (210), and opening
edges (26) extending at least partially about the tunnel axis (X) and delimiting a
tunnel inlet opening (28) open on the outer hull surface (210), wherein the opening
edges (26) extend along the tunnel axis (X) between an inner edge section (265) incident
to the tunnel axis (X) and connected to the tunnel walls (27), and an outer edge section
(267) incident to the tunnel axis (X) and connected to the outer hull surface (210);
- a grid (4) associated with the transverse maneuvering tunnel (25), comprising a
plurality of crosspieces (42) and/or a plurality of uprights (41) incident to one
another, mainly extending over a grid surface (45) incident to the tunnel axis (X)
and the outer hull surface (210);
wherein the transverse propulsion device is
characterized in that the grid (4) comprises at least one crosspiece (42) extending over the grid surface
(45) between:
• an inner crosspiece end (421) mechanically connected to the inner edge section (265)
or to a portion of the tunnel walls (27) proximal to said inner edge section (265),
and
• an outer crosspiece end (422) mechanically connected to the outer edge section (267)
or to a portion of the opening edges (26) axially enclosed between the inner edge
section (265) and the outer edge section (267) .
2. A ship transverse propulsion device according to claim 1, wherein the grid surface
(45) is substantially a grid plane (45).
3. A ship transverse propulsion device according to claim 1 or claim 2, wherein the grid
(4) comprises at least one crosspiece (42) extending over the grid surface (45) between
an inner crosspiece end (421) mechanically connected to the inner edge section (265)
and an outer crosspiece end (422) mechanically connected to the outer edge section
(267).
4. A ship transverse propulsion device according to any one of the preceding claims,
wherein all the uprights (41) are positioned substantially orthogonally to the flow
direction (S).
5. A ship transverse propulsion device according to any one of claims 1 to 3, wherein
at least one upright (41) is substantially in the shape of a polyline or broken straight
line and comprises at least two upright segments (417, 419) mainly extending over
two mutually distinct, incident imaginary straight lines (R1, R2) mainly extending
over the grid surface (45).
6. A ship transverse propulsion device according to claim 5, wherein said at least one
upright (41) comprises at least one upright segment (418) substantially orthogonally
to the flow direction (S) over the grid surface (45).
7. A ship transverse propulsion device according to any one of claims 1 to 3, wherein
at least one upright (41) is substantially curvilinear in shape.
8. A ship transverse propulsion device according to any one of the preceding claims,
wherein, along the flow direction (S), the opening edges (26) are divided into a first
edge portion (261) intended to be lapped first by the external water flow (200), and
a second edge portion (262), complementary to the first edge portion (261), wherein
the inner crosspiece end (421) is mechanically connected to the first edge portion
(261), and wherein the outer crosspiece end (422) is mechanically connected to the
second edge portion (262).
9. A ship transverse propulsion device according to claim 8, wherein, in the second half
area (282), the grid (4) cooperates with the outer hull surface (210) to form, as
a whole, a surface with a hydrodynamic shape along which the external water flow (200)
flows.
10. A ship transverse propulsion device according to any one of the preceding claims,
wherein the grid (4) extends over a curvilinear grid surface (45) and comprises at
least one crosspiece (42) having an outer crosspiece end (422) substantially tangent
to the outer hull surface (210) .
11. A ship transverse propulsion device (1), wherein the ship (2) comprises a hull (21)
which comprises an outer hull surface (210), along which an external water flow (200)
is intended to flow locally along a flow direction (S); wherein the transverse propulsion
device comprises:
- a transverse maneuvering tunnel (25) comprising tunnel walls (27) extending along
a tunnel axis (X) oriented incidentally to the outer hull surface (210), and opening
edges (26) extending at least partially about the tunnel axis (X) and delimiting a
tunnel inlet opening (28) open on the outer hull surface (210), wherein, along the
flow direction (S), the opening edges (26) are divided into a first edge portion (261)
intended to be lapped first by the external water flow (200), and a second edge portion
(262) complementary to the first edge portion (261);
- a grid (4) associated with the transverse maneuvering tunnel (25), comprising a
plurality of uprights (41) and a plurality of crosspieces (42) incident to one another,
mainly extending over a grid surface (45) incident to the tunnel axis (X) and the
outer hull surface (210); wherein the tunnel inlet opening (28) is divided into a
first half area (281) partially delimited by the first edge portion (261), and a second
half area (282) complementary to the first half area (281) and partially delimited
by the second edge portion (262);
wherein the transverse propulsion device is
characterized in that, in the first half area (281), the grid (4) is lowered with respect to the outer
hull surface (210), along the tunnel axis (X) and towards the interior of the volume
of the ship (2) defined by the outer hull surface (210) .
12. A ship transverse propulsion device according to any one of the preceding claims,
wherein the grid (4) is mechanically connected to the tunnel walls (27) in a removable
manner, for example, by means of bolted screws connected to fixing ledges (275) protruding
from the tunnel walls (27) and/or the opening edges (26), with the hull (21) being
immersed in water.
13. A ship transverse propulsion device according to any one of the preceding claims,
wherein all or only some uprights (41) and all or only some crosspieces (42) delimit
a plurality of functional through windows (40) therebetween, wherein, with the external
water flow (200) flowing along the flow direction (S) at high speeds, preferably speeds
exceeding 4 meters per second, the grid (4) is configured to prevent or limit the
passage of the external water flow (200) through said functional through windows (40).
14. A ship transverse propulsion device according to claim 13, wherein the functional
through windows (40) have a main dimension in a direction incident or substantially
orthogonal to the flow direction (S).
15. A ship transverse propulsion device according to claim 14, wherein an upright distance
(D) along the flow direction (S) between two consecutive uprights (41), which delimit
a functional through window (40) therebetween, is between 150 and 250 millimeters,
preferably between 180 and 220 millimeters.
16. A ship transverse propulsion device according to any one of claims 13 to 15, wherein
the functional through windows (40) are configured to retain water at low speeds,
preferably speeds below 2.5 meters per second, at said functional through windows
(40) and/or inside the transverse maneuvering tunnel (25) close to said functional
through windows (40).
17. A ship transverse propulsion device according to any one of the preceding claims,
wherein, in an inactive configuration, with the transverse maneuvering tunnel (25)
at least partially filled with water and the external water flow (200) flowing along
the flow direction (S) at high speeds, preferably speeds exceeding 4 meters per second,
the functional through windows (40) are configured to cooperate with one another and
keep the water inside the transverse maneuvering tunnel (25) at low speeds along the
tunnel axis (X), preferably speeds below 2.5 meters per second.
18. A ship transverse propulsion device (1), wherein the ship (2) comprises a hull (21)
which comprises an outer hull surface (210), along which an external water flow (200)
is intended to flow locally along a flow direction (S); wherein the transverse propulsion
device comprises:
- a transverse maneuvering tunnel (25) comprising tunnel walls (27) extending along
a tunnel axis (X) oriented incidentally to the outer hull surface (210), and opening
edges (26) extending at least partially about the tunnel axis (X) and delimiting a
tunnel inlet opening (28) open on the outer hull surface (210), wherein the opening
edges (26) substantially form a straight corner or comprise a flaring between the
outer hull surface (210) and the tunnel walls (27); wherein the opening edges (26)
extend between a first edge section (273) flush with the outer hull surface (210),
and a second edge section (270) inside the transverse maneuvering tunnel (25) and
spaced apart, along the tunnel axis (X), by an amount between 400 and 600 mm from
the first edge section (273);
- a grid (4) associated with the transverse maneuvering tunnel (25), comprising a
plurality of crosspieces (42) and/or a plurality of uprights (41) incident to one
another, mainly extending over a grid surface (45) incident to the tunnel axis (X)
and the outer hull surface (210);
wherein the transverse propulsion device is
characterized in that the grid (4) comprises at least one crosspiece (42) extending over the grid surface
(45) between:
• an inner crosspiece end (421) mechanically connected to the second edge section
(270) or to a portion of the tunnel walls (27) proximal to said second edge section
(270), and
• an outer crosspiece end (422) mechanically connected to the first edge section (273)
or to a portion of the opening edges (26) axially enclosed between the first edge
section (273) and the second edge section (270) .