Abstract The cross-flow vortex-induced vibration features of a submerged floating tunnel element, which is composed of two rigidly connected cylinders in a tandem configuration, were investigated via a self-oscillation model test in a steady flow. The Reynolds number ranged from 2 × 104 to 9 × 104, and the ratio of the center-to-center distance between the two cylinders and cylinder diameter varied within a range of 2-4. The vortex induced vibration responses and lift forces on the up- and downstream cylinders were studied under different spacing ratios and compared with those on a single cylinder. The results show that the spacing ratio plays an important role in VIV until the ratio reaches 4. For a small spacing ratio, a significant difference between the lift forces on the up- and downstream cylinders appears and induces a large torsional moment. For the convenience of engineering application, a torsional coefficient was proposed. The maximum torsional coefficient can reach 2.9, 1.2 and 0.98 for spacing ratios of 2, 3 and 4 at the reduced velocity of 5, respectively. Considering the vortex induced vibration responses as well as the torsional moment, a spacing ratio of 3 was recommended for tandem floating tunnel design.

中文翻译：

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双管水下浮动隧道管片模型涡激振动试验研究

摘要 通过稳态流动中的自激振荡模型试验，研究了由两个刚性连接圆柱体串联构成的沉水浮式隧道单元的错流涡激振动特性。雷诺数范围为2×104～9×104，两圆柱中心距与圆柱直径之比在2-4范围内变化。研究了不同间距比下上下游气缸上的涡激振动响应和升力，并与单个气缸上的进行了比较。结果表明，间距比在 VIV 中起着重要作用，直到该比值达到 4。对于小间距比，上汽缸和下游汽缸上的升力之间出现显着差异并引起大的扭矩。为了工程应用的方便，提出了扭转系数。间距比为 2、3、4 时，最大扭转系数分别达到 2.9、1.2 和 0.98，减速速度为 5。考虑到涡激振动响应以及扭矩，建议采用 3 的间距比进行串联浮动隧道设计。