Flow past a rotating cylinder is investigated using a two-dimensional discrete vortex simulation method in this study. The simplified Navier–Stokes equation is solved based on the relationship between the surface pressure gradient and the generated surface vortex strength. The Reynolds number based on the cylinder diameter and flow velocity is 10⁵. The non-dimensional rotation rate, α (the ratio of the cylinder surface velocity and flow velocity), is varied between 0 and 19, and four different wake formations (vortex shedding, weak vortex shedding, wake, and rotating wake formations) have been derived by the imposed rotation. The relationship between the hydrodynamics and wake formation is illustrated. Under vortex shedding and weak vortex shedding formations, periodical hydrodynamics is induced. Under wake formation, no gap between the positive-vorticity and negative-vorticity layers results in the steady hydrodynamics. The separation of the rotating wake induces the huge fluctuation of hydrodynamics under rotating wake formation. These are significant for a flow control technique and for the design of ocean and civil engineering structures. With the increasing rotation rate, the variation of mean hydrodynamics has been discussed and the maximum mean hydrodynamics is considered to be decided by the rotation rate. According to these wake formations, the vortex shedding, weak vortex shedding, wake, and rotating wake areas are identified. Combining the initial, increasing, and equivalent areas for mean hydrodynamics, two different area-divisions have been conducted for mean hydrodynamics and the relationship between the two area-divisions has been illustrated. Finally, the disappearance of vortex shedding and variation of the Strouhal number have been discussed in detail. The critical value for the disappearance of vortex shedding is α ≈ 3.5, and the Strouhal number remains steady initially and then decreases.

中文翻译：

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高雷诺数流经旋转圆柱体的离散涡分析

在本研究中，使用二维离散涡流模拟方法研究了通过旋转圆柱体的流动。简化的Navier–Stokes方程是根据表面压力梯度与生成的表面涡旋强度之间的关系求解的。基于气缸直径和流速的雷诺数为10 ⁵。无量纲旋转率，α（汽缸表面速度与流速之比）在0到19之间变化，并且通过施加的旋转获得了四个不同的尾流形式（涡流脱落，弱涡旋脱落，尾流和旋转尾流形式）。说明了流体动力学和尾流形成之间的关系。在涡旋脱落和弱涡旋脱落形成下，诱发了周期性流体动力学。在尾流形成下，正涡旋层和负涡旋层之间没有间隙，不会导致稳定的流体动力学。旋转尾流的分离引起旋转尾流形成时流体动力学的巨大波动。这些对于流量控制技术以及海洋和土木工程结构的设计非常重要。随着转速的增加，讨论了平均流体动力学的变化，并且认为最大平均流体动力学由转速决定。根据这些尾流的形成，可以确定涡旋脱落，弱涡旋脱落，尾流和旋转尾流区域。结合平均流体力学的初始，增加和等效区域，对平均流体力学进行了两个不同的区域划分，并说明了两个区域划分之间的关​​系。最后，详细讨论了旋涡脱落的消失和Strouhal数的变化。涡流消失消失的临界值为 并确定旋转的尾流区域。结合平均流体力学的初始，增加和等效区域，对平均流体力学进行了两个不同的区域划分，并说明了两个区域划分之间的关​​系。最后，详细讨论了旋涡脱落的消失和Strouhal数的变化。涡流消失消失的临界值为 并确定旋转的尾流区域。结合平均流体力学的初始，增加和等效区域，对平均流体力学进行了两个不同的区域划分，并说明了两个区域划分之间的关​​系。最后，详细讨论了旋涡脱落的消失和Strouhal数的变化。涡流消失消失的临界值为α听，说：3.5，Strouhal数保持稳定最初和随后减小。