Flow around an oscillating circular disk at low to moderate Reynolds numbers

Tian, Xinliang and Xiao, Longfei and Zhang, Xiangdong and Yang, Jianmin and Tao, Longbin and Yang, Dan (2017) Flow around an oscillating circular disk at low to moderate Reynolds numbers. Journal of Fluid Mechanics, 812. pp. 1119-1145. ISSN 0022-1120

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    Abstract

    Direct numerical simulations of the flow induced by a circular disk oscillating sinusoidally along its axis are performed. The aspect ratio of the disk is 10. The Reynolds number , based on the maximum speed and the diameter of the disk, is in the range of . The Keulegan-Carpenter number is in the range of . Five flow regimes are observed in the considered-space: (I) axisymmetric flow (AS), (II) planar symmetric flow in the low-region (PSL), (III) azimuthally rotating flow in the low-region (ARL), (IV) planar symmetric flow in the high-region (PSH) and (V) azimuthally rotating flow in the high-region (ARH). The critical boundaries between different flow regimes are identified based on the evolutions of the magnitude and direction of transverse force acting on the disk. For the non-axisymmetric flow regimes, the flow is one-sided with respect to the axis of the disk and is associated with a non-zero mean value of the transverse force acting on the disk.