基于流固耦合方法的船舶破冰阻力参数敏感性研究

Study on sensitivity parameters of ship’s ice breaking resistance based on fluid-structure interactions method

本文基于带有塑性应变失效准则的弹性断裂失效模型建立平整冰有限元模型,采用LS-Dyna流固耦合方法对船舶在平整冰条件下航行的冰载荷开展了数值模拟,选取航速和平整冰厚度作为敏感性参数,分析了参数变化对破冰阻力的影响。研究发现:各方向上的冰载荷在时域上均存在一定的周期性,冰层在船艏撞击和浮力作用下,通常以多种破坏模式的混合方式同时出现;船舶在平整冰环境下的破冰阻力随航速和冰厚的提高基本呈线性增加的趋势,不同航速及冰厚条件下的破冰阻力数值计算结果与Lindqvist经验值的误差分别在-7.5%~13.1%和-10.8%~19.4%范围内,采用LS-Dyna流固耦合方法对船舶破冰阻力进行预报具有较高精度。

The finite element model of level ice is established based on the elastic fracture failure model with plastic strain failure criterion.The LS-Dyna fluid-structure interactions(FSI)method is used to simulate the ice loads of the ship sailing under level ice conditions.The ship velocity and level ice thickness are selected as sensitivity parameters.The effect of parameters on ice breaking resistance is analyzed.The study found that the ice loads in all axial directions have a certain periodicity in the time domain.Under the action of the ship's impact and buoyancy,a mixture of multiple failure modes on the level ice usually occurs.The ice breaking resistance of the ship in the level ice environment increases linearly with the increase of the ship velocity and level ice thickness.The difference of ice breaking resistance between simulation results and the Lindqvist empirical value error under different ship velocity and level ice thickness conditions is within the range of-7.5%~13.1%and-10.8%~19.4%,respectively.The LS-Dyna FSI method has good accuracy in predicting the ship's ice breaking resistance.