On the use of several compact methods for the study of unsteady incompressible viscous flow round a circular cylinder
The unsteady viscous flow past a circular cylinder is studied numerically by means of several compact methods. In doing so, authors solve the incompressible Navier-Stokes equations in ''stretched'' polar coordinates in their vorticity stream function formulation. Fourth order accurate methods of ''Mehrstellen''-type (operator compact implicit technique) are compared to second order accurate methods applied to the study of the separated flow around a circular cylinder at several Reynolds numbers. The impulsively started cylinder at \(Re=200\) and 500 is considered without symmetry restrictions. Computational results include the bulge phenomenon at \(Re=200\), the occurrence of secondary vortices depending on the numerical schemes used at \(Re=550\), and of twin secondary vortices at \(Re=3000\). Moreover, the Kármán vortex street is investigated at \(Re=200\) with a uniform flow in the far field and with superimposed motions of the cylinder. In the latter case, a frequency analysis allows a critical examination of results pertaining to locked-in situations with regard to confinement effects.
scientific article; zbMATH DE number 4005821
scientific article