Numerical simulation on forced convection over a circular cylinder confined in a sudden expansion channel

Numerical simulations are presented for a 2-D, incompressible, crossed Poiseuille flow over a circular cylinder confined in a sudden expansion channel. The SIMPLE algorithm with the QUICK scheme is employed. The simulations are carried out for Reynolds number, Re, varying from 10 to 300, the expansion ratio of the channel, Er, ranging from 1 to 4, and the position of the circular cylinder, Xc, ranging from 1 to 15. The results show that the heat transfer mechanism is a complex function of Re, Er and Xc. Steady-state, periodical oscillating and chaotic solutions are obtained and the route of flow state from steady state to chaotic oscillation is not unique. For the fixed Er and Xc, the time-averaged Nusselt number, Nut¯, is an increasing function of Re. For the fixed Re, the heat transfer intensity depends on the flow pattern decided by both Er and Xc.