Low-Reynolds-number flow around an oscillating circular cylinder using a cell viscousboundary element method

Flow elds from transversely oscillating circular cylinders in water at rest are studied by numerical solutions of the two-dimensional unsteady incompressible Navier{Stokes equations adopting a primitivevariable formulation. These ndings are successfully compared with experimental observations. The cell viscous boundary element scheme developed is rst validated to examine convergence of solution and the in uence of discretization within the numerical scheme of study before the comparisons are undertaken. A hybrid approach utilising boundary element and nite element methods is adopted in the cell viscous boundary element method. That is, cell equations are generated using the principles of a boundary element method with global equations derived following the procedures of nite element methods. The in uence of key parameters, i.e. Reynolds number Re, Keulegan{Carpenter number KC and Stokesʹ number , on overall ow characteristics and vortex shedding mechanisms are investigated through comparisons with experimental ndings and theoretical predictions. The latter extends the study into assessment of the values of the drag coe cient, added mass or inertia coe cient with key parameters and the variation of lift and in-line force results with time derived from the Morisonʹs equation. The cell viscous boundary element method as described herein is shown to produce solutions which agree very favourably with experimental observations, measurements and other theoretical ndings