A cell boundary element method applied to laminar vortex shedding from circular cylinders

The two-dimensional unsteady incompressible Navier-Stokes equations are sol ved for flows around arrangements of circular cylinders at Reynolds number 100 and 200. A hybrid boundary element/finite element method is used to dis cretise the spatial domain together with a second order implicit finite dif ference approximation in time. The numerical scheme of study is validated f or a uniform stream past an isolated circular cylinder by comparing finding s with experimental and numerical studies. Both steady state and time depen dent solutions were predicted with good agreement. The numerical approach, known here as the cell boundary element method (cell BEM), was also used to solve flows around two cylinders of equal diameter side by side and in tan dem, It was found that no modifications to the method were needed to comput e the how field for these connected domains. In-phase and anti-phase vortex shedding modes were found to exist in the flow simulation. These simulatio ns were in excellent agreement with phenomena observed in experiments. Part icle simulations, generated from the cell BEM velocity fields, were found t o have great similarity with smoke visualisations from experiment. (C) 2000 Elsevier Science Ltd. All rights reserved.