External-opened retractable bilge keel

Abstract

The invention relates to an external-opened retractable bilge keel. A main body structure comprises two parts of a fixed shell structure (2) and a rotary shell structure (1), wherein after being closed, the two parts are in a flat shape; front and tail ends of the main body structure is shaped like a streamline; the fixed shell structure (2) is fixedly connected with a bilge strake (3); the rotary shell structure (1) is connected with the fixed shell structure (2) through a rotating shaft system; and the rotating shaft system is used for opening and closing the shell structure (1). The external-opened retractable bilge keel provided by the invention is advantaged in that the rolling damping of a ship can be increased, the rolling of the ship is effectively reduced and the rolling stability is enhanced.

Description

technical field [0001] The invention relates to a marine equipment for reducing rolling, a bilge keel that can change its shape according to changes in sea conditions, that is, a flared openable and closable bilge keel used for anti-sinking, rolling, and overturning of ships. Background technique [0002] The rolling motion of the ship is a harmful ship motion, which has adverse effects on the crew, hull structure, machinery and equipment. Ship rolling motion includes six forms: roll, pitch, bow, surge, sway and heave, among which roll has the greatest influence on ship performance, followed by pitch. In order to slow down or reduce the sway of the ship, an anti-roll device can be added to the ship. [0003] According to the essential classification of the force that constitutes the stabilizing moment, the anti-roll device can be divided into three types: gravity type, hydrodynamic type, and rotary force type; according to the control form, it can be divided into passive ty...

AI Technical Summary

Problems solved by technology

However, the existing bilge keel structure has the following defects and deficiencies: it is vulnerable to damage; it produces certain navigational resistance to the ship; it can only reduce roll, but not pitch

Moreover, limited by the size of the bilge keel, the damping moment of the anti-rolling is limited, and the ability of anti-rolling (reducing the swing amplitude) is limited. The anti-rolling effect is generally around 10% to 20%, which is difficult to meet the demand

In addition, for a certain bilge keel, due to the fixed shape and size of the bilge keel, dynamic adjustments cannot be made in response to changes in sea conditions, roll angles and accelerations, which greatly affects its application range

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