Vortex-induced vibrations (VIV) of hexagonal cylinders at Reynolds number of 1000 and mass ratio of 2 are studied numerically. In the numerical model, the Navier–Stokes equations are solved using finite volume method, and the fluid-structure interaction (FSI) is modelled using Arbitrary Lagrangian Eulerian (ALE) Scheme. The numerical model accounts for the cross-flow vibration of the cylinders, and is validated against published experimental and numerical results. In order to account for different angles of attack, the hexagonal cylinders are studied in the corner and face orientations. The results are compared with the published results of circular and square cylinders. Current results show that within the studied range of reduced velocities (up to 20), unlike circular and square cylinders, no lock-in response is observed in the hexagonal cylinders. The maximum normalized VIV amplitudes of the hexagonal cylinders are 0.45, and are significantly lower than those of circular and square cylinders. Vortex shedding regimes of the corner-oriented hexagons are mostly irregular. However, in the face-oriented hexagons, the shedding modes are more similar to the typical P + S and 2P modes.

中文翻译：

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低雷诺数下具有面角方向的六边形圆柱横流涡激振动的数值模拟

数值研究了雷诺数为1000，质量比为2时六角形圆柱体的涡激振动（VIV）。在数值模型中，使用有限体积法求解Navier–Stokes方程，并使用任意拉格朗日欧拉（ALE）方案对流固耦合（FSI）进行建模。数值模型考虑了气缸的横流振动，并针对已发表的实验和数值结果进行了验证。为了解决不同的迎角，研究了六角形圆柱在角和面方向上的位置。将结果与公开的圆形和方形圆柱体的结果进行比较。当前的结果表明，在研究的减小速度范围内（最多20个），与圆形和方形圆柱体不同，在六角形圆柱体中未观察到锁定响应。六边形圆柱的最大归一化VIV振幅为0.45，并且显着低于圆形和方形圆柱。面向角的六边形的涡旋脱落状态通常是不规则的。但是，在面向面部的六边形中，脱落模式与典型的P + S和2P模式更为相似。