Abstract
Direct numerical simulation was performed for the coexistent convection in a channel affected by the heat radiation. Four kinds of numerical condition were targeted by changing the Grashof number, Gr, and the optical thickness, T; the pure forced convection (Gr=0, τ=0), only buoyancy (Gr/10^6=1.3, τ=0) and the buoyancy with radiation (Gr/10^6=1.3, τ=0.01), (Gr/10^6=1.3, τ=0.1). According to the numerical result, buoyancy effects created the large-scale organized vortex flow all over the channel, which enhanced dramatically heat transfer. The effect of the radiation weakens the large-scale organized vortex and reduces the heat transfer by the buoyancy.
