Re=3900的圆柱绕流湍流模拟对比研究（英文）

Comparative Numerical Studies of Flow Past a Cylinder at Reynolds Number 3900

重点采用DDES和CLES研究基于Reynolds(雷诺)数3 900的圆柱绕流.大量已有实验和数值研究结果表明:圆柱后缘流动结构和回流区长度与数值空间离散格式息息相关.基于此考虑,选用了一个优化格式并通过典型的简单湍流流动和强激波流动验证了格式对多尺度结构和激波的捕捉能力.然后,分别采用DDES和CLES对基于Reynolds数3 900的圆柱进行数值模拟.通过对比圆柱表面压力分布、圆柱表面平均速度型和圆柱尾迹区的时均脉动量,发现CLES相比于DDES与实验值吻合更好.从瞬时流场来看,DDES和CLES都能捕捉丰富的流场结构,此外,CLES在物面附近区域包含更多微小脉动.最后,尽管CLES对时均脉动捕捉好于DDES,但是程序实现更加复杂.

The flow past a cylinder at a Reynolds number of 3 900 is addressed with the delayed DES （DDES） and constrained large-eddy simulation （CLES）. The experiments and numerical simulations in this case have been extensively analyzed in previous researches. It is commonly recognized that the flow structures and recirculation length are closely related to the dispersion and dissipation properties of the scheme. Under such consideration, an optimized scheme is chosen and validated for several typical flows with multi-scale structures and strong shocks. Then, the DDES and CLES are performed to obtain pressure distribution, mean velocity profiles and the turbulence statistics in the near wake. By comparing the results from calculations with the experimental data, it is found that the averaged quantities from the CLES agree slightly bet- ter with the experimental data than those from the DDES. In the instantaneous flow field, com- plicated structures are captured by both the DDES and the CLES. A sigldficant difference be- tween them is that small-scale motions can be observed in the near-wall region for the CLES. Lastly, though the CLES predicts the mean statistics slightly better, the implementation of the CLES is much more complex than that of the DDES.