Oscillating circular cylinders' force coefficients determined by a cell viscous boundary element method

Fluid forces arising from transversely oscillating circular cylinders in fluid at rest are studied by numerical solution of the two-dimensional unsteady incompressible Navier-Stokes equations defined by a primitive-variable formulation. A validated cell viscous boundary element scheme developed by the authors[1] is used ill the numerical computations. In this scheme, a hybrid approach is adopted utilising boundary element and finite element methods. Cell equations are generated using the principles of boundary element theory and the global equations are derived following the procedures of finite element methods. Flow characteristics are presented in terms of the key parameters of Reynolds number Re and Keulegan-Carpenter number KC. Drag and added-mass coefficients are calculated using the approach of Morison[2] applied to the in-line force history. Numerical results are compared with experimental findings of Kuhtz[3], analytical solutions of Wang[4] and numerical findings of Lin et al[5] in the low KC symmetrical flow regimes.