RU2240605C1 - Hydroacoustic screen on ship hull - Google Patents

Abstract

FIELD: shipbuilding, in particular, devices for reduction of ship noisiness due to installation of hydroacoustic screens on the wettable surface, which reduces the weight load on the ship and the resistance to its movement without reduction of the screen acoustic efficiency.

SUBSTANCE: the hydroacoustic screen on the ship hull has a plate of rubber-like material having through air passages hermetically sealed on both ends with layers of stiff material. The ship hull is used as one of the sealing layers, and stiff polymeric material- as the other. The screen is fenced around the edges by a coaming, the assembly of junction of the ship hull and the screen is made penetrable in the form of a belt of plates of stiff material positioned around the edges of the screen and fastened on one side to the ship hull, and on the other side - to the coaming edge. The offered hydroacoustic screen adjoining the ship board with one side not causing a noticeable growth of resistance to the ship movement makes it possible to the reduce the weight load on the ship.

EFFECT: enhanced acoustic protection of the ship and reduced noise pollution of the world ocean.

1 dwg

Description

The invention relates to noise suppression devices and can be used to reduce ship noise by installing sonar screens on their wetted surface. A large number of sonar screens are known from the patent and scientific literature, for example, a screen made of porous rubber (see US Pat. No. 3,094,696), which is a layer of porous rubber applied to a noisy structure.

The disadvantage of this device is its low strength under the action of a hydrodynamic flow flowing around the ship.

Closest to the proposed technical solution in terms of technical nature and the achieved effect is an acoustic absorber and an insulator according to US patent No. 4164727 (publ. 08/14/79, IPC G 10 k 11/00), consisting of a perforated plate of rubber-like material, sealed according to the ends with layers of hard material (metal). However, the known device significantly increases the weight load on the vessel due to the layers of metal and, in addition, when used on ships, increases the resistance to movement of the vessel and the load on the screen mount due to poor flow around the end surfaces of the screen.

The objective of the present invention is to reduce the weight load on the vessel and reduce the resistance to its movement without reducing the acoustic efficiency of the screen.

This is achieved by the fact that the hydroacoustic screen on the hull of the vessel, including a plate of rubber-like material, having through air channels, hermetically closed on both sides by layers of rigid material, the hull of the vessel is used as one of the sealing layers, and the other is a rigid polymer material; the screen around the perimeter is protected by coaming, and the interface unit of the ship’s hull with the screen is made permeable in the form of a belt of plates of rigid material located along the contour of the screen and fastened on one side with the hull of the vessel, and on the other with the edge of the coaming.

The implementation of the outer sealing layer of the screen in the form of an oil-benzo-ozone-resistant material of a polymeric material makes it possible to reduce the weight characteristics of the screen and to ensure the operation of the hydro-acoustic screen in the conditions of water polluted by oil products, as well as under the conditions of exposure to solar radiation.

Fencing along the perimeter of the hydroacoustic screen by coaming increases the strength of the screen fastening to the hull under the action of the oncoming flow.

The conjugation of the outer layer of the screen with the hull of the vessel using a fairing provides a smooth flow around the screen and a small increase in resistance to movement of the vessel.

The invention is illustrated in the drawing.

A hydroacoustic screen 2 is installed on the wetted part of the ship’s hull 1, ensuring tightness, consisting of a plate of rubber-like material 3 penetrated (perforated) by air channels 4 and closed by a plate 5 outside in the form of a sealing layer of a polymeric material with oil-benzo-ozone-resistant properties. The screen is fenced around the perimeter by coaming 6, which is fastened to a plate of rigid material along line 8, forming a water-permeable fairing 7, connected to the hull of the vessel on the other side along line 9.

The proposed device is exposed to the hydrodynamic flow that occurs when the vessel is moving.

The device operates as follows.

Under the influence of vibrations caused by marine engines and mechanisms, the hull of the vessel 1 becomes an emitter of acoustic energy into the water. On the path of propagation of acoustic energy is the proposed sonar screen, which works efficiently due to isolation and sound absorption.

In the rubber-like material 3, deformations of the sound compression-rarefaction of the screen are converted to shear deformations of the above material, which are intensively absorbed.

The absorption and isolation of noise in the screen is ensured by the airtightness of the air channels 4. This is ensured by the ship’s hull 1 and a plate of oil-benzo-ozone-resistant polymer 5 having a stiffness significantly (2-5 times) higher than the stiffness of a perforated rubber-like material 3. The polymer plate performs its functions reflected in her name. Due to the presence of the fairing 7, smoothly changing the cross section of the vessel, the flow on the screen does not cause a noticeable increase in resistance to movement of the vessel.

Permeability of a fairing for water allows to avoid self-oscillating processes associated with the penetration and development of unsteady air bubbles inside the fairing. Coaming 6, protecting the screen from hydrodynamic forces on the flow side, increases the reliability of fastening the screen on the ship's hull, which can be provided with a suitable adhesive.

Thus, the proposed hydroacoustic screen adjacent to one side of the ship, without causing a noticeable increase in resistance to the movement of the ship, can reduce the weight load on the ship, compared with the prototype screen, increase the acoustic protection of the ship and reduce noise pollution of the oceans.

Claims (1)

A hydroacoustic screen on the ship’s hull, including a plate of rubber-like material, having through air channels, hermetically closed on both sides by layers of rigid material, characterized in that the hull of the ship is used as one of the sealing layers of the screen, and the outer layer is made in the form of oil-benzene ozone-resistant polymer layer, while the hydroacoustic screen is fenced along the perimeter of coaming, and the outer layer of the screen is interfaced with the hull of the vessel using a fairing made in the form of a permeable belt a stin of rigid material located along the contour of the screen and fastened to the hull of the vessel and to the outer edge of the coaming.