Numerical study of vortex shedding from a rotating cylinder immersed in a uniform flow field

A numerical study is made of the unsteady two-dimensional, incompressible f low past an impulsively started translating and rotating circular cylinder. The Reynolds number (Re) and the rotating-to-translating speed ratio (alph a) are two controlled parameters, and the influence of their different comb inations on vortex shedding from the cylinder is investigated by the numeri cal scheme sketched below. Associated with the streamfunction (psi)-vortici ty (omega) formulation of the Navier-Stokes equations, the Poisson equation for psi is solved by a Fourier/finite-analytic, separation of variable app roach. This approach allows one to attenuate the artificial far-field bound ary, and also yields a global conditioning on the wall vorticity in respons e to the no-slip condition. As for the vorticity transport equation, spatia l discretization is done by means of finite difference in which the convect ion terms are handled with the aid of an ENO (essentially non-oscillatory)- like data reconstruction process. Finally, the interior vorticity is update d by an explicit, second-order Runge-Kutta method. Present computations fal l into two categories. One with lie = 10(3) and alpha less than or equal to 3; the other with Re = 10(4) and alpha less than or equal to 2. Comparison s with other numerical or physical experiments are included. Copyright (C) 2000 John Wiley & Sons, Ltd.