摘要
The spectrum characteristics and wake structures for a circular cylinder oscillating in a wake are investigated by use of the currently modified virtual boundary method. A forced system of two cylinders with a small spacing (the downstream one is made to oscillate in the transverse direction) is studied and interesting flow characteristics are observed. A vortex switch and the change of vortex modes (between 2S mode and 2P mode) are observed in the “lock in' region. Vortex bands are formed and lost with the increasing excitation frequency. Information concerning saddle points in the flow field is obtained for different excitation frequencies. For a forced system of two cylinders with a large spacing, the upstream cylinder sheds vortexes because there is no downstream cylinder oscillating in the wake. No distinct “lock in' response is found for the downstream cylinder.
The spectrum characteristics and wake structures for a circular cylinder oscillating in a wake are investigated by use of the currently modified virtual boundary method. A forced system of two cylinders with a small spacing (the downstream one is made to oscillate in the transverse direction) is studied and interesting flow characteristics are observed. A vortex switch and the change of vortex modes (between 2S mode and 2P mode) are observed in the “lock in' region. Vortex bands are formed and lost with the increasing excitation frequency. Information concerning saddle points in the flow field is obtained for different excitation frequencies. For a forced system of two cylinders with a large spacing, the upstream cylinder sheds vortexes because there is no downstream cylinder oscillating in the wake. No distinct “lock in' response is found for the downstream cylinder.
出处
《海洋工程：英文版》
2004年第3期391-402,共12页
China Ocean Engineering
基金
TheresearchprojectwassupportedbytheNationalNaturalScienceFoundationofChina (GrantNo .1 0 2 72 0 94)
