论文标题
一种实验模态测试方法，用于围绕气缸的亚临界流量
An experimental modal testing method for subcritical flow around a cylinder
论文作者
论文摘要
流体流的模态分析对于了解流动物理和流体 - 固体相互作用机制以及实施流量控制至关重要。与不稳定的流动不同，亚临界流的内在衰减导致未能清楚地提取亚临界流量模式。为此，本文提出了一种用于亚临界流的模态测试方法。使用动态模式分解（DMD），首次在实验中首次提取亚临界雷诺数在亚临界雷诺数处的圆柱体围绕流动式的流动模式。模式的提取结构和参数与文献中的数值结果非常吻合。发现可以在雷诺数低至19.3的雷诺数下观察到一阶vonKármán模式，该模式非常接近亚临界涡流诱导振动（VIV）的下边界。这种实验性观察阐明了vonKármán模式与亚临界流中流体 - 固定相互作用的不稳定性之间的相关性。
Modal analysis of fluid flows is essential to understand flow physics and fluid-solid interaction mechanisms, and to implement flow control. Unlike unstable flow, the intrinsic attenuation of subcritical flow has led to failures to experimentally extract the subcritical flow modes clearly. To this end, this paper proposes a modal testing method for subcritical flows. Using Dynamic Mode Decomposition (DMD), dominate modes of flow around a cylinder at subcritical Reynolds numbers are extracted experimentally for the first time. The extracted structures and parameters of the modes are in good agreement with the numerical results in the literature. It is found that the first-order von Kármán mode can be observed at a Reynolds number as low as 19.3, which is very close to the lower boundary of subcritical vortex induced vibrations (VIV). This experimental observation elucidates the correlation between von Kármán mode and fluid-solid interaction instability in subcritical flows.
