基于格子玻尔兹曼方法的二维柔性梁与刚性方柱相互作用的数值研究

Numerical study of interaction between 2D flexible beam and rigid square cylinder with lattice Boltzmann method

建立一套适用于处理刚体-柔性体-流体的复杂流固耦合问题的数值方法,即浸入边界法、格子Boltzmann方法、时间异步算法相结合的数值算法。对均匀来流中单根梁的周期性摆动、带弹性支承的方柱振动进行数值模拟,并将模拟结果与已有研究成果进行对比分析,结果发现本文采用的数值方法可以很好地模拟刚体-柔性体-流体的复杂流固耦合问题。然后对低雷诺数下(Re=100),流向角α=45°时,带弹性支承方柱后有柔性梁的流固耦合振动情况进行研究,通过分析方柱的振幅和升阻力系数,探讨方柱振动响应随折减速度的变化规律,以及周围流场的流态与其演变过程。

In this paper,a numerical method was established to deal with complex fluid-structure coupling problems of rigid body-flexible body-fluid,which was a numerical algorithm combining the immersed boundary method,lattice Boltzmann method and time asynchronous algorithm.The periodic oscillation of a single beam and the vibration of a square cylinder with an elastic support in a uniform flow were numerically simulated,and the simulation results were compared with the existing research results.The results show that the numerical method used in this paper can well simulate the complex fluid-structure coupling problem of rigid body-flexible body-fluid.Then,the fluid-structure interaction vibration of the flexible beam behind the square cylinder was studied under low Reynolds number(Re=100)when the flow approaching angle was 45°.By analyzing the amplitude and lift/drag coefficient of the square cylinder,the variation rule of the vibration response of the square cylinder with reduced velocity,as well as the flow pattern of the surrounding flow field and its evolution process were also discussed.