Stern structure of ship

Abstract

A stern structure of a ship having a uniaxial ship type stern / hull with an overlapping propeller, wherein the rear end angle a, in plan view, of the stern / hull (S) in the vertical range of at least 0.4 R (R means the radius of propeller) from the axes of the propellers (1) and (2) is set to 15 DEG or below relative to the centerline of the hull and a virtual width (on both sides of the centerline) at the tip position when the plan view is extended to the tip is set to 600 mm or shorter. Also, bracket fins (8) may be installed between stern tubes (3a) and (4a) in which propeller shafts (3) and (4) are inserted and the stern / hull (S). In addition, a wake improving fin (13) for improving wake distribution accelerated by the rotation of the forward propeller (2) and flowing into the rearward propeller (1) may be installed on the stern / hull (S) on the upstream sides of the propeller shafts (3) and (4).

Description

technical field

[0001] The present invention relates to a stern structure of a ship provided with an overlapping propeller (abbreviated as OLP) for reducing the support force of the propeller and occurrence of cavitation. Background technique

[0002] With the increase in size and speed of ships, the load on the propeller on a single-shaft ship increases, and the efficiency of the propeller decreases. In order to increase propeller efficiency and improve propulsion performance, there is a technology to equip two propellers. When equipped with two propellers, the load on each propeller is halved and the efficiency of the propellers is improved. In this case, it is important to avoid increasing the resistance of the hull as much as possible and not to reduce the efficiency of the hull, and double contra-rotating propellers and superimposed propellers are known as existing technologies capable of meeting these requirements.

[0003] Among these, there is a superimposed propel...

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