Abstract Mixing downstream of a moving square cylinder placed inside a square section channel was analyzed experimentally and numerically at blockage ratio 2 / 5 and Reynolds 200. Three frequencies were considered for the prescribed sinusoidal, constant amplitude, cylinder motion: 0.5 f 0 , 1 f 0 and 2 f 0 , where f 0 stands for the frequency of the first instability of the wake in the unmoving cylinder case. Mixing was quantified by computing the downstream standard deviation of the distribution of virtual particles seeded behind the cylinder. Experimental PIV frames were used to evaluate mixing at the channel symmetry plane. Numerical streak-lines were used to compute mixing at the full section of the channel. The power required to move the cylinder was computed as well. It was found that maximum mixing efficiency combined with minimum motion power occurred for the frequency 1 f 0 , proving that optimum mixing does not necessarily require high frequencies and/or high input power.

中文翻译：

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在高度受限的流动中由方形棱柱的规定横向振荡产生的节能混合

摘要 在阻塞比为 2 / 5 和雷诺数为 200 的情况下，对放置在方形截面通道内的移动方形圆柱体下游的混合进行了实验和数值分析。对于规定的正弦、恒定振幅、圆柱体运动，考虑了三个频率：0.5 f 0 , 1 f 0 和 2 f 0 ，其中 f 0 代表在圆柱体不动的情况下尾流的第一不稳定性的频率。通过计算在圆柱体后面播种的虚拟粒子分布的下游标准偏差来量化混合。实验 PIV 框架用于评估通道对称平面的混合。数字条纹线用于计算通道全段的混合。还计算了移动圆柱体所需的功率。