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发布时间:2019-03-09
论文类型:期刊论文
发表时间:2010-03-01
发表刊物:CHINA OCEAN ENGINEERING
收录刊物:Scopus、ISTIC、EI、SCIE
卷号:24
期号:1
页面范围:135-144
ISSN号:0890-5487
关键字:vortex-induced vibration; forced vibration; overlapping grid; large eddy simulation; modulation
摘要:Numerical simulations of a low-mass-damping circular cylinder which can oscillate freely at transverse and stream-wise directions are presented in this work. The Navier-Stokes equations are solved with finite volume method, and large eddy simulation of vortex is also performed in the calculation. In order to implement dynamic mesh, overlapping grids are generated to lessen the computation for mesh field itself. Self-excited vibrations are firstly calculated to obtain the average amplitudes and frequencies of the target circular cylinder in the current flow situation, and then forced oscillations are implemented with parameters obtained in vortex-induced vibrations previously. With slight amplitude modulation, time series of displacements in vortex-induced vibrations are essentially harmonic. Regarding the fluid force, which are larger in forced oscillations than those in corresponding self-excited cases because the fluid subtracts energy from the forced cylinders. The phase angles between forces and displacements are 0 degrees and 180 degrees for self-excited case and forced case respectively. In vortex-induced vibrations, the interactions between fluid and structure produce some weakly energetic vortices which induce the modulations of amplitude and frequency.