Amplitude responses of a square cylinder undergoing vortex-induced vibrations in the laminar regime

This paper presents a numerical study on the vortex-induced vibrations (VIV) of a square cross-section cylinder in the steady current. A new branch of high amplitude of responses (HB) was observed in the laminar regime, in agreement with a handful studies on the topic. In addition, this new branch is found to be dependent on several controlling parameters, including the approaching direction of the flow relative to the square cylinder, the Reynolds number (Re), the mass ratio, as well as the number of degree-of-freedom. In the laminar flow regime, it is found this new branch only occur when Re is greater than a critical value and only when the vibration of the square cylinder is two-degreeof- freedom. The range of reduced velocity where the HB regime occurs strongly depends on above listed parameters