Investigation of trimaran slamming under different conditions

Abstract

In this paper, the slamming pressure and load characteristics of a trimaran cross-section under various conditions were investigated by CFD (Computational Fluid Dynamics) simulations. The computation model was first validated against experimental results. After that, the simulation of different types of motion, i.e. free fall with different mass and entry velocity, entry with constant velocity and harmonic motion with different entry velocities were analysed. It was found that the characteristics of the dynamics during slamming strongly correlates to penetration depth, regardless of the types of entry. Distinguishing features during the wet-deck slam were observed for free fall motion under different conditions, including pressure drop under the main hull during wet-deck slam. The maximum acceleration would start to decrease after the mass has reached a certain value, and the second acceleration peak (corresponding to the wet-deck slam) would be smaller than the first one if the falling height is large enough.