圆柱结构顺流向第一不稳定区内涡激振动的研究

In-line vortex-induced vibration of a circular cylinder in the first instability range

在实际工程中圆柱结构顺流向的涡激振动比较常见,其对结构的疲劳破坏影响也十分显著。该文分析了弹性支承圆柱在顺流向第一不稳定区内的涡激振动,运用Van der Pol方程描述对称旋涡脱落的尾迹特性,采用尾流振子模型计算结构响应,并研究了质量-阻尼参数和质量率对顺流向涡激振动的影响机理。数值计算结果表明,在第一不稳定区内,弹性支承圆柱顺流向涡激振动存在临界质量率。

The phenomena of In-line vortex-induced vibrations appear commonly in industry, and it has an obvious effect on structural fatigue and failure. In this paper, the in-line vortex-induced vibration （VIV） characteristics of a circular cylinder in the first instability range are investigated; the near wake dynamics related with the fluctuating nature of symmetric vortex shedding is described using the van der Pol equation. The influences of mass-damping parameter, mass ratio and structural damping on cylinder in-line VIV are discussed. It can be found that a critical mass ratio exists.