Ship equipped with air bubble type drag reducing device and method for reducing drag of ship

Abstract

A ship (1) provided with a bubble resistance reduction device for supplying air bubbles or a gas-liquid mixed fluid from an air bubble supply hole (10) provided to a hull (2), and leading the air bubbles to the bottom of the ship to reduce the friction resistance of the hull (2), wherein a bow bulb (3) provided to the bow of the ship is configured from a downward-flow-promoting type of bow bulb having an increased effect of leading flowing water in the bow portion to the bottom of the ship. The tip position (Pb) of a ship-bottom flat part (2f) is between X2, which is rearward from a forward perpendicular (F.P.) by at least 0.7% of a length between perpendiculars (Lpp), and X1, which is rearward by no more than 5% of the length between perpendiculars (Lpp). Air bubbles supplied from the air bubble supply hole (10) can thereby be led efficiently to the ship-bottom flat part (2f), and the air bubble supply energy for reducing the hull resistance can be reduced.

Description

technical field [0001] The present invention relates to a ship and a method for reducing the resistance of the ship provided with an air bubble type resistance reducing device which supplies air bubbles or a gas-liquid mixed fluid from an air bubble supply hole provided on the ship's hull and guides the air bubbles to the bottom of the ship to reduce the frictional resistance of the ship's hull. More specifically, it relates to a ship and a method for reducing resistance of a ship provided with an air bubble type resistance reducing device capable of efficiently guiding air bubbles supplied from air bubble supply holes to a flat portion of the ship bottom and reducing air bubble supply energy for reducing hull resistance. Background technique [0002] The reduction of the resistance of the ship is closely related to the reduction of the energy required for the ship's navigation and the reduction of the carbon dioxide produced by the internal combustion engine mounted on the s...

AI Technical Summary

Problems solved by technology

[0010] However, in the frictional resistance reducing device of this ship, although the position of the air blowing port is matched with the streamline of the existing hull shape, the following technical idea of ​​actively making the hull shape or the bow hull shape to be generated from the bow has not been conceived. The shape of the downflow from the upper part towards the flat part of the ship bottom reduces the supply energy of micro-bubbles and increases the effect of reducing frictional resistance by micro-bubbles

[0011] In addition, in the frictional resistance reducing ship of the prior art, since the gas blowing part is provided only at the part lower than the waterline of the still water surface of the ship on the side part of the ship, the following problem is not considered: when the ship is sailing, the In the bow part, the water level rises and the depth of no water increases, so a greater static pressure is applied than when the ship is stopped in still water

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