基于浸入边界-有限元法的流固耦合碰撞数值模拟方法

针对流固耦合碰撞问题，建立了流体中固体与固体碰撞界面解析直接模拟方法，采用清晰界面浸入边界法模拟流体中的动边界问题，避免了传统贴体网格方法在求解流体中存在固体间碰撞问题时网格出现负体积的问题，采用基于罚函数的有限元方法对固体的运动和碰撞进行求解，以分域耦合方式实现流体域和固体域的耦合求解.通过与静止流体中球形颗粒与壁面正碰撞和斜碰撞的实验数据对比，验证了建立的数值模拟方法对流体中固体与固体碰撞数值模拟的正确性，获得了流体域流场在碰撞前后随时间的变化，同时通过该文建立的数值模拟方法也获得了固体域中固体的碰撞力和应力.未来，将把该数值模拟方法应用到流体流动环境中，如固体颗粒对管道的冲蚀、流体诱导海洋立管之间的碰撞、坠物对海底管道的撞击等.

Numerical Simulation of Fluid-Solid Coupling Collision Based on the Finite Element Immersed Boundary Method

A direct numerical simulation method was developed for solid-solid collision in fluid. The sharp interface immersed boundary method was used to simulate the dynamic boundary problems in fluids, which avoids the negative volume error in the body-conforming mesh method. The finite element method based on the penalty function was used to simulate the motion and collision of the solids. The coupling solution of the fluid domain and the solid domain was realized in the partitioned coupling approach. Comparison of the experimental data of normal collision and oblique collision between spherical particles and the wall verifies the validity of the numerical simulation method. The variation of the flow field before and after the collision was obtained. The contact force and stress in the solid domain were also got with the numerical simulation method. This model is applicable to fluid-flow environments such as the abrasion of solid particles on pipes, the fluid-induced collision between ocean risers, the impact of falling objects on submarine pipelines and so on.