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Indexed by:期刊论文

Date of Publication:2017-05-01

Journal:PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART M-JOURNAL OF ENGINEERING FOR THE MARITIME ENVIRONMENT

Included Journals:SCIE、EI

Volume:231

Issue:2

Page Number:496-510

ISSN No.:1475-0902

Key Words:Navier-Stokes equations; vortex-induced vibration; phase difference; energy transfer; circular cylinder

Abstract:The phase jump, energy transfer, and the associated vortex shedding modes of a circular cylinder undergoing forced oscillation normal to the incoming uniform flow are investigated numerically at Reynolds number (Re) of 200. The dependence of the fluid forces on the non-dimensional oscillating amplitude A*=A/D[0.1, 0.6] and frequency f*=f(e)/f(s)[0.5, 2.0] is examined, where A is the oscillating amplitude, D is the cylinder diameter, f(e) is the cylinder oscillating frequency, and f(s) is the Strouhal frequency of fixed cylinder at the same Reynolds number, respectively. The lock-in region is identified by the combination of Fourier analysis and Lissajous phase diagram. The phase difference between displacement and lift fluctuation and the energy transfer between fluid and structure are discussed. Within the lock-in region, a jump in the phase difference is found to occur in the cases with A*=0.5 and 0.55 without a wake mode transition. The numerical results reveal that the appearance of the phase jump is consistent with the reversal of the energy transfer direction. For the special cases of A*=0.5 and 0.55, changes in the sign of energy transfer are observed, while no reversal of energy transfer is observed at other amplitudes. The energy transfer direction is either from fluid to cylinder when A*[0.1, 0.4] or from cylinder to fluid when A*0.6. It is confirmed that the energy transfer between fluid and cylinder is not only dependent on cylinder oscillating frequency but also on cylinder oscillating amplitude.