CFD를 이용한 활주형선의 Spray Rail 부착에 따른 저항특성 연구

Abstract

The planning hull differs with the merchant ship because the planning hull has hydrodynamic force about 50%~90% of all weight uphold the hull bottom. When the fluid flow through the planning hull bottom, the pressure in the bow and stern become different. The planning condition is started when the trim occurs where the bow rise inclined along the length direction of the boat. Most of planning hull have installed the spray rail in decreasing of wave impact and improving motion performance of rolling and pitching, etc. It is known that the spray rail reduce the spray and frictional resistance by the effect of lift and improvement of wave profile in high speed. In this paper firstly, assume the planning position(trim and draft) and calculate the hull resistance by using CFD code. Next, change the trim and draft to make design point, and calculate the resistance for these points to obtain the response surface. Lastly, the optimization technique GDO(Goal Driven Optimization) provided by Ansys 12 is applied to estimate the planning hull resistance and planning position. For the high speed planning hull with and without spray rail in bottom the resistance performance analysis are performed.