Hydrofoil system of ship

Abstract

FIELD: shipbuilding.SUBSTANCE: invention relates in particular to the design of stabilizers for longitudinal and lateral roll of ships. The vessel's hydrofoil system contains stabilizer hydrofoils attached to the vessel's hull. The surface of the stabilizer hydrofoils is formed by a series of hinged flaps equipped with elastic elements, installed with the possibility of rotation from the plane of the stabilizer wing to a vertical position. The stabilizer hydrofoils are installed at an angle to the main plane of the vessel. The odd stabilizer hydrofoils are turned relative to an axis perpendicular to the centreline of the vessel in such a way that their bow is located below the stern, and the even stabilizer wings are turned so that their bow is located above the stern.EFFECT: improves the vessel's propulsion, preventing loss of control and the vessel turning broadside to the wave with subsequent capsizing, which increases navigation safety.1 cl, 4 dwg

Description

[0001] The invention relates to the field of shipbuilding and concerns stabilizers for longitudinal and lateral roll of ships.

[0002] Passive anti-roll devices are known that include a low-aspect-ratio foil device installed on the bilge curve of the vessel's hull in the form of a bilge (lateral) keel, which is represented by external longitudinal sheet or profile ties (A.N. Kholodilin, A.N. Shmyrev. Seaworthiness and Stabilization of Ships in Waves. Handbook, Leningrad: Shipbuilding, 1976, pp. 157-169). These ties form a keel wall, to the free edge of which linings are attached in the form of tubular, rod or strip-bulb profiles (according to OST5R. 1194-95), or in the form of a bent plate with a cross-section in the form of an isosceles square. The latter is rigidly attached to the keel wall. Typically, the transverse length (wall height) of the stabilizer is set to the maximum possible, at which the stabilizer does not extend beyond the dimensions of the vessel.

[0003] The disadvantage of these stabilizers is that they do not prevent a sharp drop in the vessel's speed in a developed head sea, which leads to the loss of control of the vessel and its turning broadside to the wave, followed by capsizing.

[0004] A vessel stabilizer is known, comprising stabilizer wings secured to the hull of the vessel, wherein the hull is made with recesses on the bow end, and each stabilizer wing is secured above the recess to form a volume communicating with the external environment, and with the possibility of deflection from the hull under the action of a hydrodynamic force arising when the bow end of the hull is immersed, in addition, the stabilizer wing is provided with an elastic element for pressing against the hull during surfacing (RU 2582328, IPC B 63B 39 / 06, B 63B 1 / 16, B 63B 3 / 44, published 20.04.2016).

[0005] The disadvantage of this anti-roll device is that it only reduces the longitudinal roll of the vessel and the flooding of the deck, but it cannot prevent the drop in the speed of the vessel in developed head seas, as a result of which the speed of the vessel can decrease almost to zero, which will lead to loss of control, the vessel turning broadside to the wave and its capsizing under the action of the waves.

[0006] Roll stabilizers are known, made in the form of stabilizer wings installed on the sides of the hull (V.V. Ishkov. Method of calculating loads that determine the strength of high-speed vessels with stabilizer wings. Abstract of the dissertation for the degree of candidate of technical sciences: 05.08.01 - Ship Theory and Structural Mechanics. - St. Petersburg: Central Research Institute named after Acad. P.N. Krylov, 2011, pp. 4-6), which make it possible to reduce the amplitudes of the pitching, vertical and rolling of the vessel, thereby improving its seaworthiness.

[0007] The disadvantage of these stabilizers is that they do not ensure the vessel's propulsion in developed head seas. As a result, the vessel's speed will decrease and may even reach zero. In this case, the vessel could turn broadside to the wave and capsize.

[0008] The closest analogue is the wing system of the vessel (RU 2748811, IPC B63B 39 / 06, B63B 43 / 00, published on 31.05.2021), which contains stabilizer wings installed on the hull of the vessel, consisting of flaps equipped with elastic elements, secured by hinges and resting on stops in the closed state.

[0009] A significant drawback of this vessel's foil system is that the horizontal component of the hydrodynamic force is generated on the stabilizer foils only when the bow is submerged. When the bow is rising, this force is absent, resulting in the vessel turning broadside to the wave and capsizing. Furthermore, the number of stabilizer foils is limited by the overall strength of the hull, as too many will generate a significant bending moment and increased compressive stress in the deck amidships, potentially leading to instability of the hull's structural members and subsequent failure.

[0010] The invention solves the problem of increasing the safety of navigation by eliminating a sharp drop in the speed of the vessel, which leads to loss of control, the vessel turning broadside to the wave and its capsizing in developed head seas.

[0011] To obtain the required technical result, it is proposed to install stabilizer wings, made in the form of a series of hinged flaps equipped with elastic elements, at an angle to the main plane of the vessel, with the odd stabilizer wings rotated relative to an axis perpendicular to the centerline plane of the vessel, in such a way that their bow section is located below the stern section, and the even stabilizer wings - so that their bow section is located above the stern section.

[0012] In the proposed technical solution, when the bow submerges, the flaps on the odd-numbered stabilizer wings close, and the odd-numbered stabilizer wings experience a force directed upward and in the direction of vessel motion. The flaps on the even-numbered stabilizer wings open, and the force acting on them is negligible. When the bow resurfaces, the flaps on the odd-numbered stabilizer wings open, while those on the even-numbered stabilizer wings close. This creates a force directed downward and in the direction of vessel motion on the even-numbered stabilizer wings, while the force acting on the odd-numbered stabilizer wings is negligible.

[0013] The attached graphic materials show:

[0014] Fig. 1 - general view of the ship's hull with installed stabilizer wings;

[0015] in Fig. 2 - odd wing-stabilizer with flaps in the closed position;

[0016] in Fig. 3 - odd wing-stabilizer with flaps in the open position;

[0017] in Fig. 4 - the time dependence of the total horizontal component of the hydrodynamic forces acting on all stabilizer wings.

[0018] The following symbols are used in graphic materials:

[0019] 1 - ship hull;

[0020] 2 - odd stabilizer wing;

[0021] 3 - even stabilizer wing;

[0022] 4 - hinge;

[0023] 5 - stop;

[0024] 6 - elastic element;

[0025] 7 - damper;

[0026] α - the angle of rotation of the stabilizer wing relative to the main plane of the vessel, degrees;

[0027] - horizontal component of the hydrodynamic force acting on the odd stabilizer wing when the nose tip moves downwards, kN;

[0028] - the vertical component of the hydrodynamic force acting on the odd stabilizer wing when the nose tip moves downwards, kN;

[0029] - horizontal component of the hydrodynamic force acting on the even stabilizer wing when the nose tip moves upward, kN;

[0030] - the vertical component of the hydrodynamic force acting on the even stabilizer wing when the nose tip moves upward, kN;

[0031] - the total horizontal component of hydrodynamic forces acting on all stabilizer wings, kN;

[0032] t - time, sec.

[0033] The design of the wing system of the vessel consists of odd stabilizer wings 2 and even stabilizer wings 3 installed on the hull 1 of the vessel, the surfaces of which are formed by flaps 7 equipped with elastic elements 6, secured with the help of hinges 4 and resting on stops 5.

[0034] The vessel's wing system operates as follows. In calm water, flaps 7 are pressed against stops 5 by elastic elements 6. When the vessel is moving in conditions of strong head seas, the amplitude of the vessel's heave and pitching motion increases. As the bow of the vessel's hull 1 submerges, an upward force acts on the odd-numbered stabilizer wing 2 and the even-numbered stabilizer wing 3. When acting on the odd-numbered stabilizer wing 2, this force, together with elastic elements 6, presses flaps 7 against stops 5, as shown in Fig. 2. As a result, an additional drag force is created, acting on the bow and preventing it from submerging. In this case, the downward movement of the bow of the vessel's hull 1 is accompanied by the opening of flaps 7 on the even-numbered stabilizer wing 3, as a result of which the hydrodynamic force acting on them is small.

[0035] Due to the installation of odd stabilizer wings 2 at a certain angle to the main plane of the vessel, and as a result of the rotation of the odd stabilizer wings 2 relative to the axis perpendicular to the centerline plane of the vessel, so that their bow is located below the stern, when the bow end moves downwards during vertical rolling, a hydrodynamic force will act on the odd stabilizer wings 2, which has a vertical component P ZH and the horizontal component P хн . The action of the horizontal component P хн This will prevent the vessel's speed from dropping in strong head seas and the loss of control, which will make it possible to avoid the vessel turning broadside to the wave and capsizing.

[0036] If the bow end of the hull of the vessel 1 begins to float, then under the action of the hydrodynamic force directed downwards, the flaps 7 on the odd stabilizer wings 2 rotate in the hinges 4, overcoming the resistance of the elastic elements 6, as a result of which the area of ​​the odd stabilizer wings 2 streamlined by the fluid flow decreases. This leads to a decrease in the hydrodynamic force acting on the odd stabilizer wings 2. Due to the fact that when the bow end moves upwards, the flaps 7 on the odd stabilizer wings 2 open, the hydrodynamic force acting on the odd stabilizer wings 2 is small, therefore the horizontal component P хнThe force acting against the vessel's direction of motion on the odd-numbered stabilizer foils 2 is insignificant. The upward movement of the bow of the vessel's hull 1 is accompanied by the closing of the flaps 7 on the even-numbered stabilizer foils 3, generating a hydrodynamic force on them. Its components will be directed downward and in the direction of the vessel's motion, since the even-numbered stabilizer foils 3 are installed at an angle to the vessel's main plane due to their rotation relative to an axis perpendicular to the vessel's centerline, such that their bow is located higher than their stern. This will also help maintain the vessel's speed in developed headwaters.

[0037] A specific example of the use of the proposed wing system of a vessel.

[0038] As an example of the implementation of the proposed design, let us consider a vessel 168 m long, moving in a storm in head seas at a speed of 4 knots, the wave height is taken to be 9 m. Let the vessel be equipped with a foil system of the proposed design, with the geometric characteristics of the odd stabilizer foils 2 and even stabilizer foils 3 being the same, while their length is 3 m, and the width is 1.5 m. Let 8 odd stabilizer foils 2 and even stabilizer foils 3 be installed on each side of the bow of the vessel, the interval between them is 0.5 m, and the angle of rotation of the stabilizer foils relative to the main plane is α = 15°. To model the dynamics of a vessel in such conditions, one can use the technique (Burakovsky P.E. On the issue of modeling the dynamics of a vessel in head-on waves under conditions of the bow being buried in a wave / / ​​Bulletin of the Astrakhan State Technical University. Series: Marine Engineering and Technology.- 2025 - No. 2 - P. 18-28.). Based on the results of the vessel dynamics modeling, it is possible to determine the resulting velocity and direction of the flow past the odd-numbered stabilizer foils 2 and the even-numbered stabilizer foils 3, which is composed of the velocity of water particles in the wave and the velocities of the bow due to heave and pitch, as well as the vessel's speed. At low vessel speeds, which are typically chosen by navigators when encountering a severe storm, the flow velocity past the stabilizer foils is determined primarily by the kinematics of the bow itself, characterized by heave and pitch, as well as the velocity of particles in the wave. In this case, the direction of the resulting flow velocity at the vessel's bow can be considered parallel to the plane of the vessel's midship frame, while, taking into account α = 15°, the angle of attack for the stabilizer foils will be approximately 75°.Taking into account the resulting direction of flow around the stabilizer wings, in accordance with (Grechikhin L.I. Air pressure force on a moving plate / / VOJNOTEHNICKI GLASNIK / MILITARY TECHNICAL COURIER. -2014. - Vol. LXII, No. 4. - P. 38-50, Fig. 4.) it can be assumed that the lift coefficient of the stabilizer wing is 0.35. This allows us to calculate the total horizontal component of the hydrodynamic force. acting on all odd stabilizer wings 2 and even stabilizer wings 3. The calculation results are shown in Fig. 4. As can be seen from Fig. 4, the hydrodynamic force The force generated on the stabilizer wings acts continuously, preventing the vessel from turning broadside to the wave and subsequently capsizing. This distinguishes the proposed design from the closest analog, in which a similar hydrodynamic force only acts when the bow is moving downward. Therefore, in the closest analog, when the bow rises under the action of the disturbing force, the vessel may turn broadside to the wave. This process can occur gradually, with the turning angle increasing over several successive oscillations of the vessel. This circumstance significantly reduces the effectiveness of the closest analog.

[0039] Thus, the proposed design, through the continuous action of the horizontal component of the hydrodynamic force generated by the fluid flow around the odd-numbered stabilizer foils 2 and the even-numbered stabilizer foils 3, prevents the vessel's speed from dropping in strong headwaters, thereby preventing the vessel from turning broadside to the wave and capsizing. Consequently, the proposed foil system significantly improves navigation safety in stormy conditions.

Claims

A wing system of a vessel comprising stabilizer wings secured to the hull of the vessel, wherein the surface of the stabilizer wings is formed by a series of hinged flaps provided with elastic elements installed with the possibility of rotation from the plane of the stabilizer wing to a vertical position, characterized in that the stabilizer wings are installed at an angle to the main plane of the vessel, wherein the odd stabilizer wings are rotated relative to an axis perpendicular to the centerline plane of the vessel, such that their bow section is located below the stern section, and the even stabilizer wings are rotated so that their bow section is located above the stern section.

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