计及流体影响的船舶回转冰阻力数值模拟

Numerical simulation of ice resistance of ship turning in level ice zone considering fluid effects

[目的]极地船舶在极地航行时,复杂的冰阻力不仅会给船舶带来结构上的威胁,还对船舶的操纵性提出了新的挑战,尤其当船舶在层冰区中进行转向运动时,挑战更大。近年来的研究主要集中在船—冰碰撞的强相互作用上,而少有研究流体对冰阻力的影响。[方法]采用非线性有限元法,基于适当的冰材料模型和合理的耦合破坏模式,研究船舶回转运动过程中冰与船之间复杂、强烈的非线性相互作用。同时,采用流固耦合方法,研究流体对船—冰相互作用的影响。[结果]数值结果与经验公式的对比确定了模拟的有效性与可靠性,其中对比有、无流体作用时船舶受到的纵向、横向和垂向冰阻力情况显示,计及流体影响时,船舶的冰阻力在3个自由度上会有明显提升。[结论]船舶破冰回转运动中考虑流体对冰阻力的影响,能准确预测船舶回转时的冰阻力且能有效保证船舶的航行安全。

[Objectives]When polar ships sailing in polar regions,extremely complex ice resistance not only poses structural threats to ships,but also poses new challenges for ship maneuverability,especially when the ship is turning in a level ice zone.In contrast,recent studies have mainly focused on ship-ice interaction with less consideration for the effects of fluids on ice loading.[Methods]Using the nonlinear finite element method and based on the proper ice material and reasonable coupling failure mode,the complex,strong and nonlinear interaction between ice and ship during turning motion is studied.At the same time,the fluid structure interaction method is used to consider the influence of fluid on ship-ice interaction.[Results]The validity and reliability of the simulation are determined via the numerical results and empirical formulae.The longitudinal,widthwise and vertical ice resistance of the ship are compared with or without fluid conditions.It is found that the ice load has a noticeable increase in three degrees of freedom when the effects of fluid are considered.[Conclusions]Considering the influence of fluid on ice resistance in the ship's ice-breaking movement can effectively ensure the safety of the ship and accurately predict the ice resistance when turning.