| With the development of world economy, ships, which are important trafficconveyances of world trade contacts, are moving in the direction of large scale, high speedand diversity. However, channels are becoming more and more crowed with the increase ofships. So there are more accidents happened. On the other hand, when wind, wave andcurrent effects are taken into consideration, ships will sway inevitably and a fataloperational mistake will result in serious consequences. Therefore, ship maneuverabilityand seakeeping are closely related to the safety of navigation and they must be predicted.During the process of ship design, CFD technology is used for the prediction of shiphydrodynamic performance and its movement mechanism in wave. It is of great practicalsignificance and application value for the production and construction of ships. With therapid development and wide application of computer, the computing capability of ship CFDis becoming stronger. The calculation method is continuously improved and the calculationaccuracy is gradually enhanced. So ship CFD technology is increasingly important for shipoptimization design and it will replace some part of ship model test.In this paper, S-175container ship recommended by ITTC (International Towing TankConference) is taken as the research object. First, use CFD method to predict the resistanceof the ship model. During this process, press-velocity coupled equations are solved bySIMPLEC algorithm. Second-order upwind is brought in to discrete convection terms andstandard wall function is used for the solution of near-wall region flow. k-ε,RNG k-εand SST k-ωmethod are applied to calculate the direct drag coefficient. ThenCFD is used to simulate the pure sway motion and pure yawing movement of the shipmodel. The relevant hydrodynamic coefficients are obtained when free-surface wave,possession and the change of model floatation are ignored. Finally, use the fluid dynamicssoftware HYDROSTAR to discuss the definite condition of velocity potential of low-speedship disturbance flow field based on three dimension linear potential flow theory. It alsodescribes how to use the extended boundary integral method to eliminate the irregularfrequency phenomenon. According to rigid body force theory, differential equations of ship motion are established to solve the ship motion response. |
