低速横移動する船体に働く流体力に関する研究 : 二次元CFDを用いた基礎的検討

抄録

The ship speed near the berth is very low and the fluid flow around a ship hull is unsteady. So, the transient fluid motion should be considered to estimate the drag force acting on the ship hull. Especially, the lateral motion in a berthing maneuver of a VLCC starts from the rest and ends within one ship length. In that problem, the force is usually estimated using steady state drag force coefficient obtained by towing tank experiment, although some transient force model equations were proposed by some researchers. In the low speed and short time lateral motion, the vorticity is created by the body and grows up in the acceleration stage and the velocity induced by the vorticity affect to the body in deceleration stage. For this kind of problem, CFD is considered as the good tool to understand the phenomena. In the present study, the 2D CFD code is used for basic consideration of the phenomena to solve the flow in the cross section of the ship considering the ship is slender and the water depth is large enough. The flow fields and hydrodynamic forces for the some prescribed motions are computed. The results are compared with well-known potential flow code results and the preliminary experimental results.