Numerical Simulation of Nonlinear Flow and Heat Transfer in a Sudden Expansion and Contraction Channel

Numerical simulation of forced flow in sudden-expansion followed by sudden-contraction rectangular channel was presented for the whole flow region. The nonlinear flow and heat transfer characteristics were investigated by various Reynolds number and geometrical dimension and the critical Reynolds numbers under different conditions have been calculated. The results show flow and heat transfer from symmetric state to asymmetric state with the increase of Re. When Re<Re_c (critical Reynolds number for flow transformation), the symmetric state is stable. On the other hand, when Re ≥Re_c, the flow loses stability and from symmetric to asymmetric via a symmetry-breaking bifurcation. And the heat transfer performance have relevant characteristics as fluid flow.