Abstract:Vortex-induced vibrations(VIV) of an elastically mounted square cylinder at the angle of attack were studied numerically using the spectral-element method to study the system response as a function of the spring stiffness and the mass ratio.The subharmonic mode of vibration dubbed the “higher branch” found in the experiment before was obtained.The effects of mass ratio were studied and it is found that the mass ratio has a great influence on the range of higher branch. The frequency contents of time traces of displacement and lift coefficient were obtained by taking Fourier transform.The main frequency contents, mass ratios and stiffness were composed into a series of effective rigidities. The higher branch exists in the regime that the first effective rigidity greater than zero and the second effective rigidity less than zero. There is a critical mass ratio and when the mass ratio is greater than that, the higher branch disappears. In addition, the fundamental frequency can be 1/2St,1/3St,1/4St.
汤兆烈,周本谋. 有攻角方柱涡致振动的数值研究[J]. 振动与冲击, 2019, 38(22): 124-129.
TANG Zhaolie,ZHOU Benmou. Numerical simulation of the vortex-induced vibration of a square cylinder at the angle of attack. JOURNAL OF VIBRATION AND SHOCK, 2019, 38(22): 124-129.
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