Numerical simulation of two-dimensional cross flow past a cylinder using an unstructured mesh based fully implicit second order coupled method

This paper discusses the computation of unsteady two-dimensional incompressible viscous flow on unstructured cell-centered collocated grids using a finite volume technique. A fully second order coupled resolution method is presented for solving unsteady Navier-Stokes equations, an alternative to classical segregated approaches, like SIMPLE or P1SO. Whereas the segregated methods lead to a sequential resolution of discrete equations and under-relaxation procedures, with the fully coupled method, only one linear system in velocity-pressure is solved, no relaxation or special treatment is required to ensure convergence, as equation coupling is done implicitly. The non-linear effects are thus handled better, and the non-linear residues convergence is considerably accelerated. Robustness and efficiency, ability and accuracy of this method are demonstrated to simulate unsteady flow around a cylinder at various Reynolds numbers.