An experimental modal testing method for subcritical flow around a cylinder

Modal analysis of fluid flows is essential for understanding flow physics and fluid–solid interaction mechanisms implementing control. Unlike unstable flows, the intrinsic stability subcritical has led to failures in experimentally extracting clear structure modes. To this end, paper proposes an experimental modal testing method flows. Using dynamic mode decomposition, dominant modes around a cylinder at Reynolds numbers are extracted first time. The parameters agreement with numerical results literature. It found that first-order stable von Kármán can be observed number as low 19.3, which nearly identical lower boundary vortex-induced vibration. This finding provides evidence correlation between instability