Numerical analysis of resistance reduction by bubbly layer for deep-Vee ship

A numerical analysis of resistance reduction by bubbly layer for deep-Vee ship was carried out by using the air-liquid mixture model.The effect of the factors,such as air flow rate,speed,navigation states,air injection location,stern flaps,on resistance reduction rate was investigated.The findings are obtained as follows:(1) If air is injected into water from the ship bottom,the resistance reduction rate increases with air flow until it reaches the saturate level;(2) The reduction rate is not monotonously influenced by the speed;(3) The rate decreases while the trim angle of the hull increases;(4) The reduction rate can be increased to 12% maximally by setting multi-air-injection inlets;(5)Stern flap can increase the rate about 1.57%,due to the improvement of navigation states.