2005 年 21 巻 p. 569-574
This paper presents the results of numerical simulations on the unsteady flow fields around a circular cylinder placed in asymmetrico scillatoryp lus mean flows. The correspondingfl uid forces actingo n the cylinder are also examined. Systematic computations are carried out using the two-dimensional Navier-Stokes equations in a generalized curvilinearc oordinate.T he asymmetricv elocityp rofile ofthe cnoidal waves is adopted for the oscillatoryv elocity fluctuation. The effects of the co-existing currents on the vortex motion and the fluid forces are investigated for various flow conditions. The structures of the wake vortices are described in detail, and the dependence of the maximumf luid force on the superimposedc urrenta re clarified.