Excitation force reducing type ship

Abstract

Disclosed is an excitation force reducing type ship. An excitation force reducing type ship according to one embodiment of the present invention comprises: a hull having a rear end with a propeller; and an excitation force reducing module which forms an air layer for generating reflected waves on a surface of the hull neighboring the propeller during an operation of the propeller so as to reduce the excitation force in the direction of the hull, wherein the excitation force reducing module can be arranged eccentrically with respect to a center line penetrating through the center of the axis of rotation of the propeller in a vertical direction of the hull.

1 . An excitation force reducing type ship comprising:
 a hull having a propeller provided at the stern;   an excitation force reducing module for reducing an excitation force toward the hull by forming an air layer that generates reflected waves, on a surface of the hull neighboring the propeller during an operation of the propeller,   wherein the excitation force reducing module is arranged to be deviated to one side with respect to a center line that passes through a rotational axis of the propeller in a vertical direction of the hull.   
     
     
         2 . The excitation force reducing type ship of  claim 1 , wherein the air layer that is formed by the excitation force reducing module is formed in a partial area of the surface of the hull neighboring the propeller. 
     
     
         3 . The excitation force reducing type ship of  claim 1 , wherein the excitation force reducing module is arranged to be deviated to one side in a direction in which the propeller rotates, with respect to the center line. 
     
     
         4 . The excitation force reducing type ship of  claim 1 , wherein the excitation force reducing module forms an air layer on the surface of the hull by ejecting air in a direction from the stem to the stern of the hull. 
     
     
         5 . The excitation force reducing type ship of  claim 1 , wherein the excitation force reducing module comprises a protruding portion that is coupled to a wall surface of the hull and protrudes from an outer surface of the hull, and the excitation force reducing module forms an air layer on the surface of the hull by generating air bubbles on the outer surface of the hull through an air bubble ejection hole that is formed in the protruding portion. 
     
     
         6 . The excitation force reducing type ship of  claim 5 , further comprising a porous cap that is coupled to an area of the air bubble ejection hole. 
     
     
         7 . The excitation force reducing type ship of  claim 5 , further comprising a bottom plug that is coupled to a wall surface of the hull and to which the excitation force reducing module is detachably coupled; and
 a compressed air supply portion for supplying compressed air to the excitation force reducing module.   
     
     
         8 . The excitation force reducing type ship of  claim 7 , wherein the compressed air supply portion comprises:
 a compressor provided at one side of the hull;   a compressed air supply line for directly connecting the compressor and the excitation force reducing module; and   at least one valve provided on the compressed air supply line and regulating a flow of compressed air flowing along the compressed air supply line.   
     
     
         9 . The excitation force reducing type ship of  claim 7 , wherein the excitation force reducing module comprises:
 a module body comprising a compressed air flow line that is formed in the module body, through which compressed air supplied by the compressed air supply portion flows, the module body being coupled to a penetration portion of the bottom plug by being inserted therein and comprising the protruding portion formed at one side of the module body; and   a body flange formed at the other side of the module body and arranged on a support seat of the bottom plug.   
     
     
         10 . The excitation force reducing type ship of  claim 9 , wherein the protruding portion comprises:
 an inclined wall portion connected to one side of the module body to be inclined; and a vertical wall portion arranged perpendicularly from an end portion of the inclined wall portion toward a surface of the module body.   
     
     
         11 . The excitation force reducing type ship of  claim 9 , wherein the compressed air flow line comprises:
 a linear section portion extending along a lengthwise direction of the module body; and   a cross section portion arranged inside the protruding portion to cross the linear section portion and comprising the air bubble ejection hole that is formed at an end portion of the cross section portion.   
     
     
         12 . The excitation force reducing type ship of  claim 11 , wherein an arc type guide portion for guiding the compressed air is further provided between the linear section portion and the cross section portion. 
     
     
         13 . The excitation force reducing type ship of  claim 11 , wherein the linear section portion and the cross section portion are provided independently in multiple numbers. 
     
     
         14 . The excitation force reducing type ship of  claim 1 , further comprising:
 a pressure fluctuation detection unit provided on the hull and detect pressure fluctuation occurring during an operation of the propeller; and   a controller for controlling generation of air bubbles through the excitation force reducing module based on information output from the pressure fluctuation detection unit.   
     
     
         15 . The excitation force reducing type ship of  claim 9 , further comprising a line opening/shutting module that is provided on the compressed air flow line of the excitation force reducing module and selectively opens/shuts an opening of the compressed air flow line. 
     
     
         16 . The excitation force reducing type ship of  claim 15 , wherein the line opening/shutting module is a non-powered line opening/shutting module that opens the compressed air flow line when the compressed air is supplied through the compressed air flow line and shuts the compressed air flow line when the supply of the compressed air is discontinued. 
     
     
         17 . The excitation force reducing type ship of  claim 16 , wherein the non-powered line opening/shutting module comprises:
 a ball member arranged in the compressed air flow line and opening/shutting the compressed air flow line; and   a first elastic member coupled to the ball member and compressed to allow the ball member to open the compressed air flow line when the compressed air is supplied and expands to allow the ball member to shut the compressed air flow line when the supply of the compressed air is discontinued.   
     
     
         18 . The excitation force reducing type ship of  claim 17 , wherein the non-powered line opening/shutting module further comprises:
 a ball chamber provided on the compressed air flow line and forming a space where the ball member is accommodated, the space comprising a portion having a width that is relatively smaller than that of a downstream portion in a direction in which the compressed air flows; and   an elastic member support portion provided in the ball chamber and supporting the first elastic member.   
     
     
         19 . The excitation force reducing type ship of  claim 16 , wherein the non-powered line opening/shutting module comprises:
 a line opening/shutting plate rotatably arranged in the compressed air flow line and selectively opening/shutting the compressed air flow line;   a second elastic member coupled to the line opening/shutting plate and elastically biased in a direction in which the line opening/shutting plate is returned to the original position; and   a stopper provided on a wall body of the compressed air flow line and restricting pivoting of the line opening/shutting plate.