有限流道内低雷诺数二维圆柱绕流数值模拟

为揭示尾迹流场特性及其演化规律,采用多块辐射型网格,以计算流体力学软件FLUENT为平台,对有限流道内低雷诺数二维圆柱绕流进行数值模拟,讨论压力速度耦合算法、压力离散格式和动量方程离散格式对模拟结果的影响。研究结果表明:动量方程离散格式对数值模拟误差的形成起主要作用,较佳数值模拟算法为SIMPLEC压力速度耦合、二阶压力离散和QUICK动量方程离散的组合。尾迹流场中静压在沿轴向2.6～12倍流道宽度范围内波动较显著;并且随着流速增大,轴向压降最大点越靠近圆柱,径向静压幅度变化越大。

Numerical simulation of two-dimensional flow around a circular cylinder at low Reynolds numbers in finite channel

To reveal the characteristics and the evolution of cylinder wakes,two-dimensional flow around a circular cylinder at low Reynolds numbers in finite channel was numerically simulated on the computational fluid dynamics code FLUENT using the multi-block radial girds.The effects of pressure-velocity coupling,pressure discretization,and momentum equation discretization on the computation accuracy were discussed.The results show that the discretization scheme of the momentum equation contributes principally to the formation of errors.The combination of SIMPLEC,second-order pressure discretization,and QUICK is found to be more appropriate for the simulation of the two-dimensional flow around a circular cylinder at low Reynolds numbers in a finite channel.It is also found that the static pressure fluctuates markedly along the channel axis within 2.6-12 times of the channel’s width.With the increase of the flow velocity,the position of the maximum pressure drop moves towards the circular cylinder,and the magnitude of the radial static pressure increases.