Abstract In order to understand the effects of synthetic jets on the active control of two-degree-of-freedom (2DOF) vortex-induced vibrations (VIVs) of a circular cylinder, a series of numerical simulation were carried out at Reynolds number of 150. The synthetic jet excitation frequency was fixed at five times of the natural frequency of the cylinder in still water. The influence of two key parameters of synthetic jets, the position angle (α) and the momentum coefficient (Cu), on 2DOF VIVs was analyzed. Results indicated that both in-flow oscillation and cross-flow oscillation can be suppressed when the synthetic jets with sufficient momentum coefficient were positioned at the circular cylinder's leeward side (0° ≤ α ≤ 75°). When Cu = 4, 15° ≤ α ≤ 60°, the reductions of cross-flow and in-flow oscillation amplitudes were all larger than 99% and 70%, respectively. Besides, the in-flow oscillation frequency was locked-in to the excitation frequency of synthetic jets when the in-flow oscillation was effectively suppressed. A symmetric wake can be observed when the cross-flow oscillation was completely suppressed, and the 2P+2S vortex pattern can be observed when Cu = 4, α =165° and 180°.

中文翻译：

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使用一对合成射流在低雷诺数下控制圆柱的二自由度涡激振动：位置角和动量系数的影响

摘要 为了解合成射流对圆柱体二自由度（2DOF）涡激振动（VIVs）主动控制的影响，在雷诺数为 150 时进行了一系列数值模拟。 . 合成射流的激励频率固定在静水中圆柱体固有频率的五倍。分析了合成射流的两个关键参数位置角 (α) 和动量系数 (Cu) 对 2DOF VIV 的影响。结果表明，当具有足够动量系数的合成射流位于圆柱体的背风侧（0°≤α≤75°）时，可以抑制流入振荡和错流振荡。当 Cu = 4, 15° ≤ α ≤ 60°, 横流和流入振荡幅度的降低分别大于99%和70%。此外，当流入振荡被有效抑制时，流入振荡频率被锁定到合成射流的激发频率。当横流振荡完全被抑制时，可以观察到对称尾流，当Cu = 4，α = 165°和180°时可以观察到2P + 2S涡流图案。