Investigation of the parameters of a spiral cylindrical body in a completely submerged state

One of the main problems in SWATH ship is the excessive increase of the wet surface due to the presence of the hulls below. Increasing the wet surface increases the resistance force and as a result the use of powerful engines in this type of ship. The purpose of this paper is to investigate the effect of spiraling the lower bodies and its effect on reducing the resistance force in a completely submerged state. In this paper, first, the effect of spiraling the lower bodies using a numerical method is compared. After proving the effectiveness of the proposed method, various parameters of the spiral body such as spiral depth, spiral length and rotation angle were examined. By integrating the optimized state of each of the parameters, a new spiral body was presented in which the resistance force was significantly reduced compared to the initial state.By reducing fuel consumption by spiraling submerged hulls, a new step will be taken to optimize Swath vessels.