Reduction ship skin resistance by injection small bubbles

Ship total resistance is including skin resistance, wave-making resistance and wind resistance. In which, the main factor of ship resistance is skin resistance. This paper shows a study on reduction ship resistance via reduction skin resistance by injection small bubbles. When a solid body moves on or under water surface, for skin resistance to be generated, the solid body must be in contact with the water. Skill resistance is generated by the difference in velocity between the solid object and the water. Injection small bubbles is a skin resistance reduction method that reduces skin friction of the ship moving in water by injecting small bubbles into the turbulent boundary layer developing on the ship skin. This method is expected to reduce up to 80% of ship skin resistance. Author found that this resistant reduction method could be applied to large ships not high speed movement. A model that is scaled 1/33 of a 20000 ton cargo ship had been created for carrying out experiments in a towing tank. Experimental results show that total ship resistance is reducing up to 22.5% between using and not using small bubble injection method.