METHOD OF REDUCING UNDERWATER SOUND OF SHIP PROPELLED BY PROPELLING DEVICE

摘要

PURPOSE: To create air bubbles of a proper size and an air bubble zone of a proper shape behind marine vessels by feeding air and gas just near or behind propeller devices such that the turbulence of the propeller flows causes strong mixing of the air/gas and water and the disintegration of air bubbles and that the majority of the air bubbles made in the gas-water mixture behind the marine vessels has a specific diameter. CONSTITUTION: A marine vessel 1 for towing has in the bows two propeller devices 5 just about or behind which great numbers of air blowing outlets 7 are defined. The air blowing outlets 7 jet air to cause strong mixing of the air with water and the disintegration of air bubbles. The majority of the air bubbles in the gas-water mixture behind the marine vessel 1 is from 1 to 20 mm in diameter. This process simply controls the number and size of air bubbles to thus damp sound.