EP0058682A1

EP0058682A1 - Monohull motor boat

Info

Publication number: EP0058682A1
Application number: EP81902273A
Authority: EP
Inventors: Jean-Paul Charbonnier
Original assignee: ATELIERS ET CHANTIERS de la MANCHE
Current assignee: ATELIERS ET CHANTIERS de la MANCHE
Priority date: 1980-08-29
Filing date: 1981-08-14
Publication date: 1982-09-01
Also published as: BR8108768A; NO821337L; DK190982A; WO1982000812A1; OA06880A; AU7530181A; JPS57501475A; GR78958B; IT8149115A0; ES504812A0; FR2503083A2; IT1143411B; ES8206329A1

Abstract

Navire a moteur monocoque comprenant un moteur (2) pour actionner une helice (3) et une manche a air (4) pour injecter de l'air sous la partie arriere de la coque (8) par une buse (7). L'helice (3) est placee en avant de la zone de soufflage d'air pour lui permettre de fonctionner en milieu dense, sans risque de cavitation et de chocs dommageables. Application aux navires a moteurs de tout tonnage.Monohull motor ship comprising a motor (2) for actuating a propeller (3) and an air hose (4) for injecting air under the rear part of the hull (8) by a nozzle (7). The propeller (3) is placed in front of the air blowing zone to allow it to operate in dense medium, without risk of cavitation and damaging shocks. Application to motor vessels of any tonnage.

Description

Monohull motor ship

The present invention relates to a monohull motor ship.

More specifically, the invention relates to a ship comprising an engine which actuates a propellant bearing on the water. This propellant can be a propeller or a planing wing moved vertically in an alternating movement and housed in a box open forwards and backwards. It can also be a reactor.

One of the most serious problems concerning the advancement of ships is that of the frictional resistance exerted by water on the hull. We tried to solve this problem by injecting a gas under the hull, generally air, so as to produce, between the water and the hull, an air mattress, or at least a water-air emulsion, which provides real lubrication.

With regard to friction, the result is satisfactory, but this process shows a serious drawback. Indeed, the propellant then works in a medium of low density, and its output is considerably lowered. In addition, cavitations appear on the propeller and quickly cause its destruction.

The present invention aims to make a ship using gas injection under the hull, and in which the drawbacks associated with the propellant are eliminated. According to the invention, the monohull motor ship comprises at least one motor for actuating a propellant supported on the water, and blowing means for injecting a gas under at least the rear half of the hull of the ship. I1 is characterized in that the propellant is located outside the part of the hull under which the gas is injected.

Thanks to this arrangement, the propellant works in a dense medium, therefore with good efficiency. In addition, all the risks of cavitation linked to the injection of air are eliminated and the deterioration of the propellant is no longer to be feared. According to an advantageous embodiment of the invention, the propellant is located under the hull of the ship, in front of the part of the hull under which the gas is injected.

Not only is the blowing of gas not harmful to the propellant, but it produces a positive favorable effect by promoting the evacuation towards the rear of the jet expelled by the propellant.

According to a preferred embodiment of the invention, the bottom of the ship is concave downward and comprises at least one portion of cylinder with an axis parallel to the longitudinal plane of symmetry of the ship, so as to properly hold the gas blanket.

The bottom of the ship can advantageously include two cylinder portions with a concavity directed downwards and substantially symmetrical with respect to the longitudinal plane of symmetry of the ship, according to a profile called "seagull wing".

According to different versions, the propellant may include a rearward directed gas ejector, or a propeller, or a device with a planing wing movable in a box open towards the front and towards the rear of the ship, such as that described in French Patent No. 1,418,806.

In all cases, it is advantageous for the propellant to be adjustable.

The directional effect is also achievable by a rudder located in the front half of the ship, and aft of the propellant.

The ship can also advantageously comprise two daggerboards arranged obliquely and symmetrically with respect to the longitudinal plane of symmetry of the ship, located in the front half of the ship behind the propellant and selectively liftable.

This characteristic allows, in rectilinear operation, to suppress the drag of the rudder.

According to a preferred embodiment of the invention, the propellant is vertically adjustable in position, according to a more or less accentuated planing. According to an improved embodiment of the invention, the ship comprises two propellants aligned one behind the other along the longitudinal axis of the ship, the propellant located at the rear being a speed propellant, and the propellant located at the forward being a thruster.

In a particular embodiment of the invention, the ship comprises an inclined rear deck to allow the boarding of a water skier, this arrangement being made possible by the absence of a propeller at the rear.

In an application intended more particularly for ships of large tonnage, two hollow side pins are provided extending on either side of the bottom, connected to the blowing means and pierced with holes on their wall facing the longitudinal median plane of the ship. Preferably, these pins are also pierced with holes on their walls facing the outside of the ship, and the sides of the ship are inclined, from bottom to top, towards the outside of this ship. In this way, a gas mattress is produced in the best conditions, both under the ship and on its sides.

In addition, the bottom of the ship has a gas injection nozzle located in the third araridα ship, aft of the propellant, directed towards the rear of the ship, connected to the blowing means, and extending between the two keels. in the longitudinal plane of symmetry of the vessel The gas injection nozzle advantageously comprises two lips extending transversely to the vessel, one being movable relative to the other.

Other features and advantages of the invention will emerge from the detailed description which follows.

In the appended drawings, given by way of nonlimiting examples:

. Figure 1 is an elevational view in partial section of a ship according to the invention;

. Figure 2 is a sectional view along II-II of Figure 1; . Figure 3 is a view similar to Figure 2, but according to an alternative embodiment of the bottom;

. Figure 4 is a view similar to Figure 1, but according to an alternative embodiment of the blowing; . Figure 5 is a view similar to Figure 1, but in an embodiment with two propellants;

. Figure 6 is a view along VI-VI of Figure 5;

. Figure 7 is a diagram for explaining the operation of the embodiment of Figures 5 and 6;

. Figure 8 is a bottom view of a ship with two retractable fins, along line VIII-VIII of Figure 9; . Figure 9 is a sectional view along line IX-IX of Figure 8; . Figure 10 is an elevational view in partial section of a ship for towing water skiers;

. Figure 11 is an elevational view of a large tonnage vessel according to the invention; . Figure 12 is a sectional view along XII-XII of Figure 11;

. Figure 13 is an enlarged sectional view of the bow of the ship of Figure 11;

. Figure 14 is a bottom view, along XIV-XIV of Figure 13;

. Figure 15 is a sectional view along XV-XV of Figure 14;

. Figure 16 is a detail view, partially broken away, of one of the hollow skittles of Figures 11 to 14; . Figure 17 is an enlarged partial view, in longitudinal section along XVII-XVII of Figure 14, at the blowing nozzle;

. Figure 18 is a simplified sectional view of a planing wing propellant. Referring to Figures 1 and 2, a ship 1 includes a heat engine 2 actuating a propeller propeller 3 located in the fore third of the ship. A windsock 4 allows air to enter through louvers 5 when the ship is in motion. This air is guided in ducts 6 to lead to a nozzle 7 located behind the propeller, directed towards the rear of the ship and extending transversely over practically the entire width of the bottom 8 of the ship. This bottom has a concavity directed downwards over the entire width of the ship (Figure 2).

According to an alternative embodiment, shown on the left part of Figure 2, a slat 9 is fixed along the shell to combat the effect of the valve.

According to another variant (Figure 3), the bottom is made in the form of two symmetrical cylindrical parts 8a, 8b having a common central edge, according to a profile called "seagull wing".

When the ship advances, the bow naturally tends to level off. In addition, the apparent wind causes an air current in the sleeve 4, which has the effect of injecting air under the hull. This air, retained in particular thanks to the concave profile of the shell, constitutes a mattress which limits the contact of the shell with water and greatly reduces friction. It has been found that, thanks to this system, the power consumed could decrease by half for equal performance.

In addition, the propeller being located outside the part of the hull under which the air is injected, it operates in a dense medium, with its best efficiency. On the other hand, it is free from shocks due to bubbles and does not risk cavitation.

According to another embodiment (FIG. 4), a vessel 11, having a concave bottom 12, comprises a compressor 13 sucking air through louvers 14 and discharging it through ducts 15 towards two nozzles 16, 17 extending over all the width of the bottom and located one behind the other. These two nozzles are selectively closable. A propeller 18, coupled to a motor not shown, is adjustable in depth by known mechanical means.

This arrangement makes it possible to use a propeller with a large pitch without knowing the drawbacks of this type of propeller at low speeds, that is to say a "stuffing" of the propeller and poor efficiency.

At low speed, the vessel did not plan much. The propeller is placed in the high position and the nozzle 16 is opened. The propeller 18 sends its jet into an air mattress which is already leaking towards the rear, which allows it not to "stuff", c that is to say to operate at its real step, and not at an apparent step which would result from the friction of the propeller jet in the surrounding water.

At high speed, the ship planes strongly. The nozzle 16 which is emerged is then closed and the nozzle 17 is opened. In addition, the propeller is lowered at 18a. This propeller then operates in deep water, without its thrust being influenced by the air mattress, which is then distant. This benefits in a wide speed range from the power, thrust and propeller speed characteristics without having to use a variable pitch propeller.

According to another alternative embodiment (FIGS. 5 and 6), a ship 21 with a concave bottom 22 is provided with two propellers 23, 24 placed one behind the other in the axis of the ship and actuated by respective motors 25, 26 placed obliquely for reasons of space. Means similar to those described above are provided for producing an air mattress under the bottom 22 behind the propellers. The front propeller 23 is at small pitch and the rear propeller 24 is at large pitch, so as to constitute respectively a thruster and a speed propeller.

FIG. 7 shows the respective thrusts P of these propellers, as a function of the speed V of the ship, following curves C23 and C24.

At low speed, the thrust of the propeller 23 is largely preponderant, while at high speed this propeller is screwed into the water without reaction and no longer has a propulsive effect, only the propeller 24 having such an effect . However, already at low speed, the propeller 23 blows the propeller 24 forward, which allows the latter to have a significant thrust at low speed before regaining its characteristics of high pitch at high speed. In all the embodiments previously described, it is provided that the propellers are rotatably mounted around a vertical axis in order to steer the ship. This directional effect is obtained with a large lever arm with respect to the uneven edges of the rear part which, in turn, effectively brake the centrifugal skid of the ship.

We will now describe, with reference to Figures 8 and 9, another ship steering system.

A ship 31, seen from below in FIG. 8, has a concave bottom 32 and is actuated by a propeller 33 located in the front third and actuated by a motor not shown. The ship also includes blowing devices (not shown) of the type described above. Ship 31 also includes two drift wells

34 in each of which is mounted a sliding fin 35.

These wells are oblique and symmetrical with respect to the longitudinal plane of symmetry of the ship and they are located in the forward half of the ship. By lowering more or less one or the other of these drifts, by jacks 36, one acts on the jet of the propeller. Of course, only one of the fins is active and located in the jet, the other remaining retracted into the hull.

Referring to Figure 10, a ship 41, having a concave bottom 42, is provided with a propeller 43 located approximately one third before. It further comprises a blowing device as described above to provide an air mattress under the hull aft of the propeller. On a winch 44 is wound a cable 45 provided with a handle 46 intended to drive a water skier. At the rear, an inclined bridge formed by rollers 47 allows the skis 48 to dock.

The skier can easily land on the ship, without any danger since the propeller is located at the front, far from the collision point.

We will now describe, with reference to Figures 11 to 17, a vessel according to the invention, but of relatively large tonnage, such as a fishing boat.

A vessel 51 has a concave bottom 52 limited on its sides by hollow pins 53. These pins have holes 54 (FIG. 16) facing the longitudinal median plane 55 of the vessel and provided with nozzles 56 directed at 45 ° towards the aft of the vessel and slightly upward so as to be approximately parallel to the concave bottom 52 in the vicinity of the edges of this bottom.

Holes 57 are also made in the pins 53 on the walls facing the exterior of the ship and are provided with nozzles 58 directed substantially parallel to the sides 59 of the ship and at 45 ° to the rear. The sides 59 of the ship are themselves inclined, widening upwards (FIG. 12).

The keels 53 are connected by pipes to compressors 61 (FIG. 12) housed in the ship.

A transverse nozzle 62 (FIG. 17) is located in the forward third of the ship. It is directed towards the rear of the ship and is situated, relative to the normal direction of travel of the ship, behind the propeller 63 (driven by a motor 70) and the rudder rudders 64. The nozzle 62 is in communication with the compressors 11 and it consists of a fixed lower lip 65 and an upper lip 66 movable by sliding on the bottom 52, so as to be able to vary the space between the lips, which determines the blowing section.

In each of the pins 53 (Figure 16) is located an axial shaft 67 which carries, opposite each hole 54, a drum 68 pierced with a hole 69 forming a shutter. The tree

67 carries a propeller 71 driven by the flow of air blown into the keel so as to operate the drum

68 in periodic shutter. The keels 53 extend beyond the nozzle at 53a (FIG. 15) up to the stem, but, from the nozzle, they no longer have an orifice and nozzles directed inward.

All along the ship, and in particular in the region of the bow, the inclination of the sides on the vertical is very small, just necessary to stick the air bubbles to the wall, but without introducing a dynamic lift effect notable.

Finally, above the waterline, the flanks and the bow change slope, moving further away from the vertical, along lines 72 and 73.

In operation, the air blown from the various nozzles constitutes, under the bottom 52, a well distributed mattress, as well as along the sides 59, so that most of the shell is thus "lubricated" by the air. However, the propeller 63 operates in open water, outside the air mattress, and is therefore not subject to any risk of cavitation or shock which could deteriorate it.

This is due to the fact that the bottom, in the region of the propeller and in the part situated in front, is no longer the seat of an air mattress, the blowing inwards does not exist.

In addition, the direction of the nozzles having a rearwardly directed component, the blowing cooperates in advancement. If the vessel tends to sink, the widened parts 72 and 73, when immersed, immediately exhibit greater resistance to sinking.

It has been found that the jerky execution of the blowing, thanks to the periodic shutter device, improves the yield. The frequency used is between 0.1 and 3 Hz or between 10 and 30 Hz.

The invention also advantageously provides for connecting the pins 53 to reservoirs of cleaning product to allow fairing on the high seas.

Similarly, instead of being uniformly concave, the bottom 52 can be composed of concave grooves.

In all the embodiments described, the fluid injected under the shell can be other than air, and for example include the engine exhaust gases, the engine being connected to the blowing nozzles by suitable pipes.

Likewise, the propellant may not be a propeller, but for example a device in accordance with that described in French Patent No. 1,418,806. Such a device comprises a box 74 (FIG. 18) fixed to the hull and open towards the forward and backward. A planing wing 75 is articulated on a rod 76 driven by an alternating vertical movement. The alternative inclination of the wing 75 causes, with the upper and lower walls of the box, a wedge of water which advances the ship.

As shown in the side views of FIGS. 1, 4, 10 and 11, the concave bottom 8, 12, 42, 52 substantially straight and horizontal in the gas injection zone, can then be curved upwards until the rear end of the hull. Two fixed, substantially triangular and vertical rudders, the lower edge of which extends the substantially straight part of the lateral edges of the concave bottom to the rear end of the hull, define with the rear part raised from the bottom 8, 12, 42, 52, a kind of nozzle promoting with surprising efficiency the flow of gases under the hull. Likewise, the motor for actuating mechanical thrusters is not necessarily a heat engine, but could be electric.

Finally, the propulsion could be carried out by ejection of gas into the water by means of an ejector directed towards the rear.

Of course, the invention is not limited to the examples described but covers any technological variant accessible to those skilled in the art.

Claims

1. Vessel with a monohull motor, comprising at least one motor (2.25, 26, 70) for actuating a propellant (3.23, 24.63) bearing on the water, and blowing means (4.13 , 61) for injecting a gas under at least the aft half of the hull (8,12,22,32,42,52) of the ship, characterized in that the propellant is located outside the part of the hull under which we inject the gas.

2. Ship according to claim 1, characterized in that the propellant (3,18,23,24,33,43,63) is located under the hull of the ship, in front of the part of the hull under which one injects the gas.

3. Vessel according to claim 2, characterized in that the bottom (8,12,22,32,42,52) of the vessel is concave downward and comprises at least a portion of cylinder with an axis parallel to the plane of longitudinal symmetry of the ship.

4. Ship according to claim 3, characterized in that the bottom (8) of the ship comprises two cylinder portions (8a, 8b) with concavity directed downwards and substantially symmetrical with respect to the longitudinal plane of symmetry of the ship.

5. Ship according to one of claims 1 to 4, characterized in that it comprises two nozzles (16,17) for blowing gas arranged one behind the other in the bottom (12) of the ship, and selectively lockable.

6. Vessel according to one of claims 2 to 5, characterized in that the propellant comprises at least one gas ejector directed towards the rear.

7. Ship according to one of claims 2 to 5, characterized in that the propellant comprises at least one propeller (3,18,23,24,33,43,63).

8. Ship according to one of claims 2 to 5, characterized in that the propellant comprises at least one planing wing device (75) movable in a box (74) open forward and aft of the ship.

9. Ship according to one of claims 6 to 8, characterized in that the propellant (3,18,23,24,43) is orientable.

10. Ship according to one of claims 6 to 8, characterized in that it comprises a rudder (64) located in the front half of the ship, and behind the propellant (63).

11. Vessel according to one of claims 6 to 8, characterized in that it comprises two fins (35) arranged obliquely and symmetrically with respect to the longitudinal plane of symmetry of the ship, located in the front half of the ship, aft propellant (33) and selectively liftable.

12. Vessel in accordance with one of claims 7 or

8, characterized in that the propellant (3,18,23,24,33,43, 74) is vertically adjustable in depth.

13. Ship according to one of claims 7 or 8, characterized in that it comprises two propellants (23, 24) aligned one behind the other along the longitudinal axis of the ship.

14. Vessel according to claim 9, characterized in that the propellant (24) located at the rear is a speed propellant, the propellant (23) located at the front being a thruster.

15. Ship according to one of claims 1 to 14, characterized in that it comprises an inclined rear deck (47) to allow the boarding of a water skier.

16. Vessel according to one of claims 3 to 10, characterized in that it comprises two hollow side pins (53) extending on either side of the bottom (52), connected to the blowing means (61 ) and drilled holes

(54) on their wall facing the longitudinal median plane

(55) of the ship.

17. Vessel according to claim 16, characterized in that the pins (53) are also pierced with holes (57) on their walls facing the outside of the ship.

18. Ship according to claim 17, characterized in that the sides (59) of the ship are inclined, from bottom to top, towards the outside of this ship.

19. Ship according to one of claims 16 to 18, characterized in that the bottom (52) of the ship comprises a gas injection nozzle (64) located in the front third of the ship, behind the propellant (63 ), directed towards the rear of the ship, connected to the blowing means (61), and extending between the two pins (53) transversely to the longitudinal plane of symmetry (55) of the ship.

20. Vessel according to claim 19, characterized in that the gas injection nozzle (62) comprises two lips (65,66) extending transversely to the vessel, one (66) being movable relative to the other (65).

21. Vessel according to one of claims 16 to 20, characterized in that the holes (54,57) formed in the hollow keels (53) are provided with nozzles (56,56) directed obliquely towards the rear of the ship.

22. Ship according to one of claims 16 to 22, characterized in that, above the waterline, the sides (9) of the ship and the bow have parts (72,73) more inclined by vertical to the parts below the waterline.

23. Vessel in accordance with one of claims 16 to

22, characterized in that the pins (53a) extend towards the front of the vessel, beyond the nozzle (62), without comprising in this region of blowing orifices directed towards the interior.

24. Ship according to one of claims 16 to

23, characterized in that each hole (54,57) of the hollow pins (53) is provided with a movable shutter (68) connected to motor means (67,71) for discovering this hole periodically.

25. Vessel according to claim 24, characterized in that the motor means of the movable shutters (68) comprise a reel (71) placed in the keel (53) to be actuated in rotation by the flow of blown gas 26. Vessel conforming to one of claims 16 to

25, characterized in that the pins (53) can be selectively connected to tanks for cleaning the hull.

27. Vessel according to one of claims 1 to 26, characterized in that the blowing means comprise an air bag (4,14).

28. Vessel according to one of claims 1 to

26, characterized in that the blowing means comprise an air compressor (13).

29. Ship according to one of claims 1 to

26, characterized in that the blowing means comprise an engine exhaust gas line.

30. Vessel according to one of claims 3 or 4, characterized in that, seen from the side, the rear part of the concave bottom (8, 12, 42, 52) is curved upwards.