抄録
2D and 3D fluid simulations for flow around an in-line forced oscillating circular cylinder have been conducted in order to clarify the mechanism of flow induced vibration. Immersed boundary method is used to solve the moving boundary. Additionally, OpenFOAM which is open source CFD-tool is used. The vibration modes of a cylinder are categorized into two excitation region in terms of the reduced velocity. In the first excitation region, it is shown that a low drag force forms by contacting between high pressure region and a circular cylinder. It is considered that a in-line oscillation of a cylinder comes from the contact phenomena. In the second excitation region, it is shown that the time averaged lift drag doesn't reach zero on some oscillating conditions. It is considered that a cross-flow oscillation of a cylinder comes from the phenomena.
