FR2837782A1 - TRIMARAN TYPE HIGH SPEED SHIP HULL - Google Patents

Abstract

The technical sector of the invention is the field of shipbuilding, more particularly the manufacture of ship hulls. The present invention relates to a high-speed ship hull comprising a central main float (1) and two lateral floats (2) of shorter length, located towards the rear of the central float (1) and connected thereto by link arms (5) ¡the hulls of said three floats (1, 2) being always submerged whatever the speed, said link arms (5) are faired in the shape of airplane wings creating, thus two nozzles (6 ) ground effect between the interior lateral surfaces emerged from the central float (1) and lateral floats (2), and the liquid surface (71) on which said hull moves. According to the invention, the upper surface of said link arms has perforations (20) and a suction system (21) allows air to be drawn through said perforations from the outside to the inside of said link arms. (5).

Description

which includes in particular a reader of this card (18).

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  TRIMARAN TYPE HIGH SPEED SHIP HULL

  The present invention relates to high-speed ships having a hull of the trimaran type. The technical sector of the invention is the field of shipbuilding and more particularly of the

manufacture of ship hulls.

  More particularly the present invention relates to ships capable of transporting passengers and / or freight such as essentially vehicles, at least m long, capable of sailing at high speed beyond knots and even 50 knots, whatever either the weather conditions and keeping a fairly good stability both in roll and in pitching on the one hand, a comfort of navigation in particular for the passengers and on the other hand, not to overstress the hull structures which must be simple to

manufacture, rigid and resistant.

  Vessels of this type have been described in WO99 / 00291 (PCT / FR98 / 01340) and the present invention relates to improvements to the vessels described in

this earlier patent.

  More particularly, the present invention therefore relates to a ship hull comprising a central main float and two lateral floats of shorter length, situated towards the rear of the central float and

  connected to it by shrouded link arms.

  According to the invention described in WO99 / 00291 (PCT / FR98 / 01340) the hulls of the three floats are always partly submerged and therefore to be considered always as a displacement hull, whatever the speed and the weather conditions. The hulls of said lateral floats include submerged adjustable fins. And, the coefficient of finesse of each of the three hulls is between 0.25 and 0.35

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  with a ratio of the length to the width of each between 9 and 20 and a length ratio of the central hull to the length of the side hulls

between 2.5 and 4.5.

  s This basic design, as specified below, with a central shell with very large elongation, offers very low drag resistance and effective behavior on short swells like those encountered in closed seas or semi-closed such as the Mediterranean or the English Channel. The t ranevereal e stability is ensured by the rear batchers who can give the hull according to the invention a qualification as a trimaran when it is in fact rather a "pseudo trimaran". Such aft floats, as defined by their precise characteristics below, confer on the vessel, unlike the catamaran, remarkable behavior because of the long period of roll that they generate. Roll is also controlled by the efficiency of the mobile stabilizing fins in alternating operation so that it is always positive, giving

  always bear upwards.

  In addition to ensure good tranevereale stability for a moderate overall width of the hull, while retaining minimum drag as well as a one-piece structure to this pseudo trimaran assembly, these small rear floats, slightly submerged, have a slenderness of their bow quite large with a V shape giving a very fine water entry, and a slight rear immersion allowing a very movement

  soft and quasutostable with speed.

  With regard to pitching, this is minimized by a shape also in a narrow V of the bow of the central float, giving a finesse of entry into the water and little slenderness, which help to qualify the hull as " wave-piercing "; the rear position of the floats tends

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  also to quickly break any pitch initiation

in the swell.

  To complete this basic design, said link arms connecting the central float to the lateral floats, according to the invention described in WO99 / 00291, are faired in the form of airplane wings thus creating two ground effect nozzles between the internal lateral surfaces emerged from the central float and the lateral floats, and the liquid surface, on which the said trimaran hull moves. This form of aircraft wing profile allows to create a lift which opposes the weight of the boat. These wing-shaped link arms are relatively small (D) but of large rope (L) and is located at a height (H) above the water of between half and a quarter of the average rope . An aerodynamic lift is thus obtained due to the dynamic pressure obtained by slowing down the air as it passes through these kinds of nozzles constituted by the undersides of the wings of the link arms joining the floats to the central hull, and the surface of

  the water. This dynamic pressure increases with speed.

  The object of the improvements which are the subject of the present invention is to improve the lift created by said link arms in the form of airplane wings since the inventor observed that, despite the relatively low speed of the ship compared to the speed of an airplane, it nevertheless occurs, as on any airplane wing profile, detachment of the laminar boundary layer of the area on the upper surface profile, ie the upper surface of said link arms. And, conventionally, a turbulent regime results which induces an increase in aerodynamic drag and a decrease in lift. Another object of the present invention is 3s to improve the air intake system necessary for the combustion of the ship's engines, because a problem arises.

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  often installed in high speed ships: the air drawn around the ship being loaded with water can be detrimental to the proper functioning of the engines. In fact, on all ships with traditional hulls, the air from the engines is usually sucked in by grids arranged transversely on the hull: thus especially for high-speed ships which therefore lift a lot of water around them. suction grids favor the entry of water and this is all the more accentuated if the wind is lateral; it is then conventionally disposed of the baffles in the suction lines but despite this and especially under the above conditions, the water ends up arriving in the motors which disturbs the operation enormously

  of these and even can stop them.

  To address the above problems, a high-speed ship hull is defined comprising a central main float and two shorter lateral floUtors, located towards the rear of the central float, connected to the latter by link arms, and preferably comprising submerged foils or fins, the hulls of said three floats being always submerged whatever the speed, and said connecting arms are faired in the form of airplane wings thus creating two ground effect nozzles between the inner side surfaces emerged from the central batch and lateral batchers, and the liquid surface on which said shell moves: according to the present invention the upper surface of each of said connecting arms comprises perforations and a system air intake capable of creating a flow of the order of at least 200,000m3 / hour (i.e. 55m3 / second) on each wing-arm, creating sufficient depression to said upper surface of the arms so that the boundary layer of the air passing against it remains glued to this surface, said air suction system sucking it through

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  said perforations, from outside to inside

said link arms.

  By "aircraft wing profile" is meant an arched profile. By "upper surface of said connecting arm" means the upper surface of said arched profile. The fact of sucking in air at the zones where the delamination of the boundary laminar layer takes place results in a reattachment of the boundary laminar layer of the air flow and therefore a reduction in the aerodynamic drag of the wing and a increase in her

  lift as will be explained below.

  In a mode of realization i sat ion prefer iel said air sucked by the suction system is used for the combustion of the engines ensuring the propulsion of the ship and preferably the dimension and the density of the perforations is determined so that the flow of air reaching the motors corresponds to the air flow

  necessary for the operation of these engines.

  Said link arms consist of a structure formed of hollow boxes and, according to the present invention, advantageously, the air is sucked through a device having a suction cavity placed inside a box constituting the structure. of said connecting arm and said suction cavity comprises means making it possible to retain the water sucked with air through said perforations and said cavity and to evacuate it to prevent it from reaching

said engines.

  Advantageously, said means for retaining water comprise a plate inclined towards the outer lateral end of said link arms and terminate at said end by a sump comprising a pipe receiving the water in

  below said plate and allowing it to be removed.

  3s In a preferred embodiment, all of said perforations on the surface of said support arms

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  link form an area extending along the rope of said link arm in the longitudinal direction XX 'of the ship over a distance ranging from 10 to 30%, preferably 15 and 25% of said rope starting from the edge of attack on said profiled link arm in the shape of an airplane wing and, more preferably, extending in the transverse direction YY 'of said link arm over at least three quarters of the transverse width

said link arms.

  Thus defined, the perforation zone being along the cord over a sector corresponding to the start of the separation of the boundary laminar layer on this type of aircraft wing profile, in particular for the aircraft wing profiles adapted to relatively low speeds,

notably less than 60 knots.

  In fact, more particularly, according to the present invention, said profile in the shape of an airplane wing of said link arm in the longitudinal direction of the ship is of the type either Gottingen G562 without flap or NACA 6412 with orientable trailing edge flap, these profiles type being known to those skilled in the art in the field of wing profiles. This arched profile of the link arm in the longitudinal direction of the ship is such that the maximum thickness of said profile, that is to say the maximum height in vertical section between upper surface (upper surface) and internal surface (lower surface), is from 20 to % of the average length of the rope, which corresponds to a relatively thick leading edge, i.e.

  rounded with a large radius of curvature.

  It is understood that the dimensions of said perforations are such that the air is sucked in at a speed greater than that of the laminar flow of air flowing in

upper surface.

  Preferably, the size and density of the 3 perforations is determined as a function of the air flow rate consumed by said motors, namely that the size

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  and the density of the perforations is determined so that the air flow reaching the motors corresponds to the flow

  of air necessary for the operation of said motors.

  Advantageously, said perforations are cylindrical perforations spaced from 1 to 5 mm and preferably inclined from top to bottom towards the rear with respect to said upper surface by an angle preferably from 30 to 60, more preferably from order of 45. It is understood that the inclination of the perforations in the thickness of the sheet metal constituting the upper surface of the wing allows more efficient suction.

  because it decreases the curvature of the air flow lines.

  According to another aspect of the present invention, the trailing edge of said wing profile of said link arms cooperates with a high-lift flap preferably of the Fowler type which makes it possible in a known manner to increase the lift of said link arm as in the NACA 6412 type profiles cited above and represented as

example in the attached figures.

  This high lift component is deployed when significant lift is required, in particular at start-up and when the ship has to cross the critical speed of around 45 knots. The increase in the lift allows the hulls to take off more and thus 2s to the boat to accelerate up to 60 knots without increase

of motive power.

  A ship according to the present invention also has the characteristics described in WOg9 / 00291 and in particular for a ship whose length Lpp as defined below, of the central float is between 50 and 150m: - said lift component makes it possible to increase the lift of said link arm at least 20% when said flap is deployed, - the fineness coefficient (or "block coefficient") of each of the three hulls, defined as the ratio of

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  volume of the submerged hull over the volume of the written parallelepiped enveloping said hull, is between 0.25 and 0.35 with a ratio of the length Lpp to the width B of this hull included in 9 and 20, and a length ratio of the central hull along the length of the lateral hulls included in 2.5 and

4.5, and preferably 2.85 and 4.

  - the coefficient of finesse of the central hull is preferably between 0.32 and 0.34 with a ratio of the length Lpp, between perpendicular front and rear of the float, over its width at the master bau at the waterline between 10 and 18 (for a length Lpp of 100m the width at the master beam could be 6m); the finesse coefficient of the hulls of the lateral floats is preferably between 0.26 and 0.28 with a

  ratio of their length to their width between 9 and 17.

  - the rear of the two lateral floats is located at a distance d between 5 and 20% of the value of the hull length of the central float forward in relation to the rear perpendicular thereof, and the longitudinal median planes YY 'of the hulls of the lateral floats are located at a distance D of between 10 and 15% of the length Lpp of the hull of the central float, on either side of the median plane XX' thereof. Preferably d is even between 10 and 15% of

Lpp and D between 12 and 14%.

  Estimates by calculations have made it possible to evaluate that for a bearing surface of each wing of these link arms of the order of 220 m 2, at a speed between 40 and 50 knots, this ground effect is obtained, and at using the - arched profile of these wing-shaped arms, a total lift of the order of at least 10% of the mass of the ship (the efficiency and the value of the lift of such wings is a function of the speed of the ship: a lift of the order of at least 10% is thus obtained from 40 knots and is even better for speeds of 60 g 2837782 knots), and this lift is improved by about 10% to% with arms-wings perforated according to the present

  invention, compared to non-perforated wings.

  In addition, other characteristics of the ships according to the invention described in WO99 / 00291 and according to the present invention supplement those presented above and provide additional advantages, namely: - the ship according to the present invention has immersed stabilizing fins attached lateral floats also called "foils". For a surface of the order of 6m2 each, at a speed of between 40 and knots, these "foils" give a downforce of approximately 60 tonnes: this gives total relief of the order of 20% of the mass d '' a vessel having a displacement of

  550 tonnes, corresponding to the surface indications above

  above, that is to say having a length of the order of

100m and considered at half load.

  - to obtain sufficient pushing to reach such speeds of at least 40 to 50 knots, propulsion is ensured by at least one jet of water and preferably two, leaving the rear part of the central float, supplemented with preferably by another water jet or "hydrojet" propellant located at the rear of each lateral float, ie a preferential total of 2 s four; the ejection nozzles of these water jets are preferably orientable upwards and downwards of the order of 12 relative to the horizontal, supplementing the above effects of the immersed fins or "foils", forms of hull and link arms in order to reduce pitching and rolling movements: for this purpose the movements of said nozzles and said fins or foils are controlled with control linked to an inertial unit; - to ensure and maintain such high speeds, due to the significant drag of the aerial parts at these speeds of more than 40 knots,

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  the aerodynamics of the aerial elements, that is to say super structures or dead works of the hull, is optimum, by giving, among other things, rounded shapes at the front ends of the hull parts concerned as for an airplane fuselage ; all of these dead works has no protuberance or edge to obtain a minimum coefficient of drag facing the wind. In addition, the central float comprises a rear aerial vertical stabilizer, fitted with a movable flap and constituting a natural stabilizer, by providing a slight support on the side opposite to the apparent wind; a balance is also established between the lift obtained by this rear spoiler, the support of which can be controlled by its movable turning flap and that of the surface of the front wall of the central float; - in order to give the ship, at a speed greater than 45 knots, a horizontal attitude and a maximum water length ensuring minimum energy consumption, the hull of the ship according to the invention has, when stationary, a slightly negative corresponding to a slight pricking of its bow. It will be noted that the conventional and known displacement ships always sink backwards when one wants to exceed 45 knots of speed: thus by rearing up, they cannot in fact exceed this speed by 45 knots. The combination of the supports of the lateral rear floats, the submerged fins and the bearing wings of the support arms prevents such a sinking and nose-up, even contributes to lifting the stern and consequently keeps the ship horizontal in these lines even at 45 knots. then allowing this speed to be exceeded; the ship according to the present invention may also include fans located at the front of the arm wings and on either side of the central hull, such as two fans per side, in order to increase the apparent wind and therefore improve the lift wings

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link arms.

  The result is a hull design with aft stabilizers, or so-called pseudotrimaran hull, of high-speed ships allowing to reach the indicated speeds and to exceed 30 to 35 knots of current ships in normal navigation, to reduce part of the hydrodynamic resistance and thus allow speeds of the order of 50 to 60 knots (100 to km / h) with still reasonable powers (35,000 horsepower for a ship according to the dimensions indicated below). In a way, from around 35 knots, thanks to the particular configuration of the hull, self-stability is created which allows to gain around 25 knots with relatively little additional power; in any event, the drag of the hull according to the invention does not increase, at these speeds above 30/35 knots, like the cube of the speed

  as is the case for other ships.

  In addition, this pseudotrimaran hull of a high-speed ship has a relatively low height on the water compared to the trimaran hulls known today: indeed, for a central hull length of 100 m and more, the overall height on the water thereof is at most m, with a height of the link arms above 2s the water between 3 and 6 m and an overall width for example

from 30 to 40 m.

  Such a hull makes it possible to transport passengers in a comfort that can be considered as equivalent to that of an airplane, and vehicles and / or containers loaded in the hold of the only central float by a rear access closed by any door of known design and which can be very simple. It is noted in fact that only the volume emerged from the central floater is fitted out for the transport of passengers and freight, the rest of the volumes being made up of watertight compartments, most of which can be filled with cell foam.

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  closed in sufficient quantity to compensate for the whole weight of the laden ship, ensuring

  unsinkability even in the event of the shell being torn.

  In addition, the structure of the central float can be oversized and thanks to a biconical shape provides the ship beam with significant rigidity so that there is no alternating stress, which makes it possible to envisage at least 25 years of service. : in fact the biconical shape is characterized by a larger cross-section in the longitudinal middle of the float than at its front and rear ends; the thickness of the hull plating can be, without greatly penalizing the total displacement, of the order of triple the prescriptions of the classification bodies, which is necessary due to the high speeds achieved and which is possible thanks to the particular concept of the ship according to the invention reducing the surfaces of the hull planking. The construction of this vessel can be carried out in a very simple or even rustic way with a mixed structure and easy to form planking. For ship realizations from 5 0 to 1 1 5 m the material chosen may be aluminum and for sizes from 120 to m steel or a mixed combination of steel and

aluminum.

  Other characteristics and advantages of the present invention will become apparent in the light of the

  detailed description which follows and with reference to

  Figures 1 to 6 in which: Figure 1 is a top view of a hull

  trimaran of a ship according to the invention.

  Figure 2 is a side view of the profile of the

  hull of a ship according to the invention.

  Figure 3A is a rear view of a hull of a

ship according to the invention.

  FIG. 3B is a rear view in median section

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  transverse of a hull of a ship according to the present invention. FIGS. 4A to 4C are views in median longitudinal section of a link arm according to the prior art (FIG. 4A), with perforations and high lift flaps in the retracted position (FIG.

  4B) and with a high lift flap deployed (Figure 4C).

  In FIG. 5A, the perforations are shown in plan view, and in FIG. 5B, the perforations in vertical section in the sheet metal constituting the

  upper surface of the link arm.

  Figure 6 is a top view of an arm of

link according to the invention.

  All of these figures therefore represent a pseuJotrimaran hull of a high-speed ship 7 comprising, in a known manner, a central float 1 and two lateral floats 21, 22 of shorter length situated towards the rear of the central float 1 and connected to this by link arms 5; the hulls of the three floats 1, 21, 22 are always submerged whatever the speed and the weather conditions and ensure navigation while maintaining the transport bridges

  almost horizontal passengers and / or cargo.

  The hulls of said lateral floats 21, 22 comprise immersed fins, or "foils", adjustable 31, 32 by an alpha angle equal to approximately 45 in the middle position with respect to the vertical median plane YY 'of each float 21, 22 and oriented towards the inside of the hull towards the central float 1: they are preferably articulated under each lateral float 2 and can tilt at least between 40 and 50; these stabilizing fins or "foils" can for example be of a so-called Vaton profile, of the type defined by the latter and as manufactured on the Charles HEIDSIEK IV boat in 1994 and to which any person skilled in the art can thus have access.

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  These three floats 1 and 2 always remain at least partially submerged regardless of the speed of advancement of said vessel and thanks to the various specific means and forms according to the invention ensure navigation in a plane which remains very close to the horizontal; the central float is designed to receive passengers on specific bridges and vehicles on other bridges; other arrangements are of course possible depending on the dimensions of this central hull and the use of such a vessel. A navigation and command bridge overlooks the entire hull and is preferably fitted on the central float 12 slightly in front of the bow

side lights 2.

  In FIGS. 4A to 4C, the fairing link arm 5 is shown in the form of a wing profile, for example of the NACA 6412 type. This fairing shape makes it possible to create a lift which is opposed to the weight of the boat. As on any wing profile, delamination of the boundary layer occurs (Figure 4A) with turbulence regimes 31 which induce greater drag and less lift. On this type of wing profile, the separation of the boundary layer occurs from L1 = 15% of the length of the rope (L) from the edge

2nd attack 51.

  To improve the lift, according to the present invention, sufficient air is sucked at this detachment to allow the bonding of the boundary layer (-figures 4B and 4C) which results in a decrease in the drag of the wing and a increased lift. This air thus sucked in is preferably used and even may be that necessary for the combustion of

main engines.

  According to the present invention as shown in 3s in FIGS. 4B, 4C, 3B, 5 and 6, microperforations 20 have therefore been produced on the upper surface of the arms.

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  5. The zone 26 of the microperforations is between 15% (L1) and 25% (L2) of the chord (L) of the wing, starting from the leading edge 51. This corresponds to the sector

  start of delamination of the boundary layer.

  s Each link arm comprises structural boxes made up of metal beams, only three of which 28, 29 and 30 are shown in dotted lines in FIGS. 3B, 4 and 6. A box is placed in the box, corresponding to the zone 26 of the micro perforations. device comprising a suction cavity 22. This device is designed to allow the water passing through the perforations 20 to flow along a plate 24 inclined in slope from the central shell 1 to the corresponding lateral floator 21, 22 in the transverse direction YY 'to flow into a sump 25 communicating 251 to the underside of the link arm. Thus water is prevented from being entrained with the air sucked towards the motor 17. IJne channel 21, ensures the circulation of the air sucked through the microperforations 20 from the suction cavity 22 above the plate 24 as far as the motor 17 which comprises air suction means. The sump 25, 251 takes the form of a gutter 2s itself logically inclined in the longitudinal direction XX 'to allow better evacuation

some water.

  As shown in Figure 6, the perforation area 26 may preferably form a parallelogram, the two longitudinal sides of which are parallel to the leading edge line 51 of the link arm. In FIG. 4C the high-lift flap 27 of the “Fowleri” type has been shown in the deployed 3s position: the flap is moved back from its folded position shown in FIG. 4B under the lower surface of the bearing wing of the link arm; it is at the same time inclined at an angle of 15 to 20 relative to the horizontal, which makes it possible to combine the effects of curvature, of slot 32 between the trailing edge 52 of the wing s and the flap 27 which reactivates flow, and the effect of surface variation, which then increases the lift

of the arm considered.

  In FIGS. 5A and 5B, the

  cylindrical microperforations 20 forming the zone 26.

  Each perforation 20 may be 1.6 mm in diameter, or approximately 2 mm2 in area. The density of the perforations corresponds in the present example to a

  9.2 mm spacing between holes.

  This density has been calculated so that the air flow sucked through the perforations corresponds to the flow of air consumed by a 8200 kW motor increased by 30% to take into account the pressure losses along the suction ducts 21 : this corresponds to a flow rate of air sucked through the perforations of 11, 6 m3 / s taking a speed of 100 km / h in the suction sections, which represent in the present example a suction surface of 0 , Approximately 5m2, the pergages being carried out on a surface of the order of 10m2. In fact the distribution and the diameter of the perforations must be such that they are not too small to avoid clogging or too large not to create problems of resistance of the structure. A person skilled in the art is able to thus define such perforations in order to obtain the flow rate or the pressure difference necessary according to the present invention. In FIG. 5B, the perforations are shown, seen in section, through a sheet of 8mm thick

  at an inclination of 45 relative to the horizontal.

  The central hull 1 can comprise two lateral keels 8 fixed on the rear part of its hull 11 and comprises a rear rudder 9 for navigation. Below the decks 13, the structure of the central hull 1 has a double bottom 18 and at the rear the machinery s 17 in which the powertrains are located, which can be hydrojets of water including the nozzles 10

  are located at the rear part of the hull.

  Such propulsion by hydrojets can be carried out by four thrusters 10, one of which is located on each lateral float 2 and two on the central hull 1 with feed water inlets 11 situated laterally towards the middle of the hull of the float considered so as not to not too much disturb the flow towards the rear part of said hull: thus such intake openings 11 are preferably positioned at a distance between 10 to 15% of the value of the length of the hull of the hull considered, ie upstream, ie downstream of the separation point of the laminar boundary layer, and their opening length must be 10 to 15% of the length of this same laminar boundary layer. In addition to facilitate maneuvers in ports, the central float 1 may include retractable bow thrusters not shown in the figures

attached.

  For hull dimensions corresponding to those given above with a central floater of length Lpp between 50 and 150m, the surface of the tail unit 4 is such that its relationship with the lateral surface of the emerged part 12 of the central floater 1 is between 0.07 and 0.09, and the surface of the fins, or "foil", stabilizers 3 with respect to the submerged hull surface of the corresponding floats 2 is

between 0.025 and 0.030.

  The orientation of the foils or ailerons 3 and of the nozzle outlets 10, is controlled by electrical controls for stabilizing the vessel linked to an inertial unit is ensured for example by a hydraulic system supported by a pneumatic emergency system which at least removes the nozzles 10 in horizontal position s in the event of a problem. This double cross-stabilization between the foils or ailerons and the nozzles, linked to the inertial unit, allows optimal comfort by controlling parasitic lateral movements knowing that such a system is almost neutral in terms of consumption.

energy.

  To give an order of magnitude of the displacement of the ships that can be produced according to the present invention, a unit with a length Lpp of 62 m has a light displacement of the order of 190 tonnes for a 1S displacement at full load of 240 tonnes; for a unit of 100 m the light displacement could be 485 tonnes and a displacement at full load of 680 tonnes and for a unit of 130 m a light displacement of about 800 tonnes for a displacement at full load of 1200

tons.

Claims (9)

  1. High speed ship hull comprising a central main float (1) and two shorter side floats (21, 22), located towards the rear of the central float (1), connected to the latter by link arms (5), and preferably comprising submerged foils or fins (31, 32), the hulls of said three floats (1,21, 22) being always submerged whatever the speed, and said link arms ( 5) are faired in the form of airplane wings, thus creating two ground effect nozzles (6) between the interior lateral surfaces emerged from the central float (1) and lateral floats (21,22) and the liquid surface (71 ) on which said shell moves, characterized in that the upper surface of said link arms comprises perforations (20) and an air suction system (21) capable of creating a flow of at least 200,000m3 / hour (i.e. 55m3 / second) on each wing-arm, creating a depression sufficient for lad ite upper surface of the arms in such a way that the boundary layer of the air passing against it remains glued to this surface, said suction system (21) for the air sucking it through said perforations of the outside towards   the interior of said link arms.   2. ship hull according to claim 1 characterized in that said air sucked by the suction system (21) is used for the combustion of   engines (17) ensuring the propulsion of said ship.   3. ship hull according to claim 2, characterized in that the dimension and the density of the perforations is determined so that the air flow reaching the engines corresponds to the air flow   necessary for the operation of said motors (17).   4. Ship hull following one of   Claims 1 to 3, characterized in that the air is 2837782   sucked through a device having a suction cavity (22) placed inside a box (23) constituting the structure of said connecting arm (5) and said suction cavity (23) comprises means ( 24, 25) for retaining the water sucked with the air through said perforations (20) and said cavity   suction (22) and evacuate (21).   5. ship hull according to claim 4, characterized in that said means (24) for retaining water comprise a plate (24) inclines towards the outer lateral end of said link arms (5) and terminate at said end by a sump (25) comprising a pipe collecting the water below said plate (24) and making it possible to evacuate it.   6. Ship hull following one of   claims 1 to 5 characterized in that the assembly   said perforations on the surface of said link arms form a zone (26) extending along the cord of said link arm in the longitudinal direction XX 'of the ship over a distance ranging from 10 to 30%, preferably 15 and 25 % of said rope starting from the leading edge (51) of said link arm and, more preferably, extending in the transverse direction YY 'of said link arm over at least three-quarters of the transverse width of said link arms link. 7. Ship hull following one of   claims 1 to 6, characterized in that the said   perforations (20) are cylindrical perforations from 1 to 5 mm in diameter, said perforations being spaced evenly from 5 to 15 mm and preferably inclined up and down towards the rear with respect to said upper surface by an angle preferably from 30   3s to 60, more preferably around 45.   8. Ship hull following one of 21 2837782   Claims 1 to 7, characterized in that the edge of   leak (52) of said wing profile of said link arms (5) cooperates with a high-lift flap (27) preferably of the Fowler type which makes it possible to increase the s lift of said link arm.   9. Ship hull following one of   claims 1 to 8, characterized in that the   coefficient of fineness of each of the three hulls is between 0.25 and 0.35 with a ratio of the length to the width of each of between 9 and 20 and a length ratio of the central hull to the length   lateral hulls between 2.5 and 4.5.   lO. Ship hull according to claim 9, characterized in that the coefficient of fineness of the central hull (1) is between 0.32 and 0.34 with a ratio of length to width between 10 and 18 and the coefficient of fineness of the hulls of the lateral floats (2) is between 0.26 and 0.28 with a ratio of their length to their width between 9 and 17 for a hull length of the central float (1) between and 150 m, and the rear of the two lateral floats (2) is located at a distance d of between 5 and 20% of the value of the hull length of the central float (1) in front with respect to the rear perpendicular thereof, and the longitudinal median planes YY 'of the hulls of the lateral floats (2) are located at a distance D of between 10 and 15% of the length Lpp of the hull of the central float (1), on either side of the XX 'median plane thereof.   11. Ship hull according to any one of   Claims 1 to 10, characterized in that it   includes propulsion means by water jet leaving the rear part of the central float (1) and side lights (21,22).