Numerical Simulation of Vortex-Induced Motion of a Circular Cylinder with Low Mass-Damping

摘要

In this paper, our in-house RANS solver, naoe-FOAM-SJTU,rndeveloped using OpenFOAM is applied to numerically simulate thernVIM of a 2-D circular cylinder with low mass-damping. The responsernand vortex modes of an elastically mounted rigid circular cylinderrnconstrained to oscillate transversely to a free stream are numericallyrninvestigated. Computations are carried out for reduced velocities fromrn1.5 to 13, corresponding to a range of 1500 to 13000 in Reynoldsrnnumber. The mass ratio is 2.4 and the mass-damping is 0.013. Thesernparameters are set to be identical with those of the benchmarkingrnexperiment conducted by Khalak and Williamson (1996). The beatingrnphenomenon in initial branch is supported by two peak in FFT analysis.rnOne difference in the response of cylinder between present study andrnexperiment results from the system's tendency to keep its earlier state.rnThe intermittent change of vortex modes at U*= 2.9375, whichrncorresponds to maximum amplitude of vibration, indicates the upperrnbranch should be described as intermittent switching between initialrnand lower branch. The computational results of response of cylinderrnand the vortex mode in the wake are in good agreement with thernexperimental results except for the absence of upper branch.