渦放出の完全ロックイン領域における不規則特性 : 渦形成長さの変動特性

抄録

In the complete lock-in phenomenon of vortex shedding with small oscillation of a body at average natural vortex shedding frequency, the flow behind the body is considered to exhibit no irregular characteristics. However, even under the complete lock-in condition, the flow behind the body, in particular the vortex formation length, was found to exhibit irregular characteristics. In this study, the time variation of the vortex formation length was investigated by image processing of flow visualization, Also the cross correlations of the vortex formation lengths between the upper and lower separated shear layers were investigated. From this study, it was clarified that the breakdown of vortex formation is associated with large vortex formation length.