平板间方柱绕流的格子Boltzmann方法模拟

为研究平板间方柱绕流上下平板对置于其中的方柱绕流所产生的影响,采用格子Boltzmann方法对二维平板间低雷诺数(Re=100)方柱绕流问题进行了数值模拟研究.分析了3种不同阻塞比下,平板边壁对方柱的升、阻力系数、Strouhal数和尾涡流场的影响.结果表明:平板对方柱绕流特性有明显的影响,随着阻塞比的增加,阻力系数和Strouhal数均增大,与无边壁相比阻力系数可增加达30%,而升力系数却随之减小.计算结果与相关实验数据相吻合,验证了格子Boltzmann方法对钝体绕流非定常问题模拟的有效性。

Numerical simulation of confined flow around a square cylinder in a channel with lattice Boltzmann method

The flow around a square cylinder confined in a two-dimensional channel is investigated for Re = 100 using the lattice Boltzmann method(LBM).Three blockage ratios are considered.The effects of channel walls on drag and lift coefficients of cylinder,Strouhal number and vortex structures in the wake of the cylinder are examined.The variations of the coefficients and the Strouhal number with the blockage ratio are presented.It is found that both the drag coefficient and the Strouhal number increase with the blockage ratio while the lift coefficient decreases.The drag coefficient increases as much as 30% compared to that for an unconfined square cylinder.The results are compared with related experimental data in literature and a good agreement is achieved.The comparison also shows that the LBM has capability in simulating bluff body flows.