RU2672227C1 - Ship hull - Google Patents

Abstract

FIELD: shipbuilding.SUBSTANCE: invention relates to the field of shipbuilding, in particular to the design of ship hulls. Ship hull is made in the form of an impermeable shell, formed of the outer skin and the beams of the set. Forward end of the hull in the upper part is streamlined, and the flat surface of the deck at the bow end is formed by collapsible beams equipped with elastic elements located in the guides fixed on the streamlined surface of the nose of the hull. Stiffness of the elastic elements is chosen so that the boules move towards the bottom when the critical value of the acting hydrodynamic force corresponding to the maximum permissible fall of the metacentric height for the given ship is reached. In the absence of external critical hydrodynamic loads, the boules are returned to their original position.EFFECT: stability loss and destruction of the ship hull is eliminated, that increases the safety of navigation.1 cl, 2 dwg

Description

The invention relates to the field of shipbuilding, in particular to the design of hulls.

A known design of the front of the displacement vessel (RU No. 2374120, IPC B63B 1/06, publ. 11/27/2009) with transverse symmetry relative to the central axis, and the hull forming lines increase in width from the baseline. The bottom is flat or has a pitch and goes into the bottom with a given radius of the bottom. From the bottom to a predetermined height, the generatrix lines are slightly inclined outward. At the level of the deck of the tank, the shape of the outward sloping line stops and passes upward in the form of a curved line back in the direction of the central axis.

This design has the following disadvantages:

- the ship has a large windage;

- the wheelhouse is removed from the engine room, which makes it difficult to lay cable routes;

- poor habitability;

- shock waves can knock out windows in the wheelhouse and lead to damage to navigation equipment;

- at a high wave height, they can overlap through the superstructure, while the flat deck surfaces will contribute to the capture of the bow of the vessel by the wave [Burakovsky EP, Burakovsky PE Some problems of ensuring the overall strength of ships in emergency situations // Transactions of the Krylov State Scientific Center - Issue. 82 (366), 2014 - S. 21-30];

- poor germination per wave, because due to the slenderness of the waterline, the ship crashes into a wave, and it twists above the bow and to the side, as a result of which the bow of the ship can be captured by the wave, which will lead to the death of the ship.

Known hull with obstruction and the reverse inclination of the stem (US No. 6601529, B63B 3/00, publ. 05.08.2003).

The disadvantage of this design is the low stability of the vessel, which can lead to capsizing and the death of the crew. This is explained by the reduced waterline area compared with the traditional design, especially when passing wave crests, as well as by the low values of the restoring moment acting on the vessel during its heeling, which is due to the small size of the vessel's volume immersed in water when tilted.

The hull of the vessel, which is an impenetrable shell consisting of thin sheets, which are supported by beams made of rolled or composite welded sections (Barabanov N.V. Design of the hull of marine vessels. L., Shipbuilding, 1981. - 552 s), was adopted as the closest analogue. ., p. 9-11, figure 1).

This design has a significant drawback consisting in the possibility of capturing the bow of the nose by the wave, which is due to the presence of flat deck surfaces and the superstructure of the tank, as a result of which a metacentric height may fall and the vessel topple over or destruction of its hull [Burakovsky EP, Burakovsky P.E. Some problems of ensuring the general strength of ships in emergency situations // Transactions of the Krylov State Scientific Center. - Vol. 82 (366), 2014.- S. 21-30]. Capture of the nasal tip by a wave means that when the deck is flooded heavily, it operates in a submerged position as a wing streamlined by a liquid stream, as a result of which pressure forces arise on flat surfaces, which is determined by the angle of attack and the speed of the incoming liquid. This flow is unstable, as a result of which the resultant can at any moment move away from the diametrical plane and cause a strong roll or tipping of the vessel, as well as the destruction of its hull. Under the action of the resultant hydrodynamic forces, the trim of the vessel increases, while there is a sharp decrease in the transverse metacentric height, which contributes to the capsizing of the vessel.

The invention solves the problem of improving the safety of navigation, excluding a catastrophic decrease in the stability of the vessel and the destruction of its hull when a nasal tip is captured by a wave due to the implementation of the nasal tip with the ability to change shape at critical values of the acting hydrodynamic force, improving streamlining, and restore the shape to its original shape in the absence of external critical hydrodynamic loads.

To solve this problem, in the hull of the vessel, made in the form of an impermeable shell formed from the outer skin and set beams, it is proposed that the hull tip in the upper part be streamlined, and the flat surface of the deck in the bow tip should be formed with boules that ensure the collapse of the side. It is proposed to equip the boules with elastic elements located in the guides mounted on the streamlined surface of the nasal tip of the body. It is proposed to choose the stiffness of the elastic elements so that the boules displace towards the bottom when the critical value of the acting hydrodynamic force reaches the maximum permissible drop in the metacentric height for the vessel and the boules return to their original position in the absence of external critical hydrodynamic loads.

In the proposed technical solution, when the hydrodynamic force acting on the nasal extremity reaches a critical value, the shifted boules shift from the deck to the bottom, resulting in improved flow around the hull of the vessel and reduced load acting on it, thereby eliminating the rollover of the vessel and its destruction corps.

The attached graphic materials show:

in FIG. 1 is a cross section of the hull in the area of the bow;

in FIG. 2 is a view A in FIG. one.

The following notations are used on graphic materials:

1 - the main part of the body;

2 - shifted boules;

3 - elastic element;

4 - guide;

5 - sliding washer.

The hull structure consists of the outer skin and the set beams forming the main part of the hull 1 and the movable boules 2, equipped with elastic elements 3, connected to the sliding washers 5 installed in the guides 4.

The hull operates as follows. When the vessel is moving in strong oncoming waves, the bow tip may periodically immerse in water, which leads to the appearance of a complex mode of flow around the deck. Under such conditions, significant loads may occur, acting on the hull of the vessel, caused by the flow around the submerged deck, which can be considered as a wing of complex shape, located at an angle of attack to the incoming liquid flow. Under the influence of hydrodynamic force, the trim of the vessel will increase, and its stability parameters will decrease sharply. In addition, there is an increase in stresses from the total bend, which can lead to the destruction of the hull [Burakovsky EP, Burakovsky PE Some problems of ensuring the overall strength of ships in emergency situations // Transactions of the Krylov State Scientific Center - Issue. 82 (366), 2014 - S. 21-30]. When the hydrodynamic force reaches a critical value in the proposed design, the shifted boules 2 will move from the deck to the bottom with overcoming the resistance of the elastic elements 3 installed in the guides 4. After the biased boules 2 are biased, the hydrodynamic loads acting on the main part of the hull 1 will decrease due to streamlined shape of the contours in the bow tip of the main part of the hull 1. This shape of the contours will reduce the load on the bow tip when it flows around the deck more than twice as compared with the construction of the closest analogue, characterized by the presence of flat deck surfaces [Burakovsky EP, Burakovsky PE Some problems of ensuring the general strength of ships in emergency situations // Transactions of the Krylov State Scientific Center. - Vol. 82 (366), 2014 - S. 21-30]. Moreover, after moving the shifted boulevard 2 to the lower position, the flow conditions of the hull of the vessel in the direction from the bottom to the deck will deteriorate, i.e. resistance to downward movement of the nasal extremity will increase, which will reduce its immersion in water and, as a result, will reduce the magnitude of the perceived hydrodynamic force. After the termination of the hydrodynamic force, the movable boules 2 will take their initial position on the main part of the hull 1 under the action of elastic elements 3. Thus, in the absence of the action of extreme loads on the bow tip, if the proposed design is implemented, the vessel will have a significant waterline area and, accordingly, have high lateral stability.

As elastic elements 3 can be used, for example, coil coil springs connected to sliding washers 5 installed in the guides 4. In this case, the sliding washers 5 must be able to move inside the guides 4, but to absorb the forces directed perpendicular to the guides. For this purpose, as guides 4, for example, a pipe with a longitudinal slot can be used, curved in the shape of the main part of the housing 1 and rigidly connected to it. In this case, the sliding washer can be made, for example, in the form of a disk with a diameter such that when it is placed in the pipe between its inner walls and the outer cylindrical surface of the disk, there is a gap of a predetermined value to ensure free movement of the sliding washer 5 along the guide (in the absence of elastic elements 3) and small displacement in the perpendicular direction. The connection of the movable boules 2 and the sliding washers 5 can be accomplished, for example, by equipping the sliding washers 5 with protrusions passing through a longitudinal slot in the pipe and extending beyond its outer surface. The movable boules 2 can be attached to these protrusions, for example, using welding, riveting or threaded connections. In this case, the displacement of the movable boules 2 and the sliding washers 5 connected to them down along the guides 4 will occur with overcoming the resistance of the elastic elements 3, the movement in the opposite direction will be carried out under the action of the elastic elements 3.

To ensure the timely movement of the movable boulevards 2, the stiffness of the elastic elements 3 should be such that their deformation will occur when a critical value of the hydrodynamic force is reached, corresponding to the maximum allowable drop in metacentric height for a given vessel, or to the maximum allowable increase in stress from a general bend in its hull. The indicated value of the hydrodynamic force can be estimated for each specific vessel using the apparatus of the theory of the ship and the structural mechanics of the ship in accordance with [Burakovsky EP, Burakovsky PE Some problems of ensuring the overall strength of ships in emergency situations // Transactions of the Krylov State Scientific Center - Issue. 82 (366), 2014 - S. 21-30].

Thus, the proposed design eliminates the loss of stability and the destruction of the hull when moving oncoming waves in stormy conditions, in contrast to the hull structure in the closest analogue, which contributes to the safety of navigation.

Claims (1)

The hull of the vessel, made in the form of an impermeable shell formed from the outer skin and set beams, characterized in that the fore end of the hull is streamlined and the flat surface of the deck at the fore end is formed by collapsing boules equipped with elastic elements located in the guides fixed on the streamlined surface of the nasal extremity of the body, the rigidity of which is selected so that there is a displacement of the boules towards the bottom when critical the magnitude of the acting hydrodynamic force corresponding to the maximum permissible drop in the metacentric height for a given vessel, and the return of the boules to their original position in the absence of external critical hydrodynamic loads.

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