Modeling of mixed convection and thermal radiation in a rectangular enclosure submitted to different ventilation modes.

In the present paper, numerical computations have been carried out to investigate the mixed convection developing within a cavity ventilated by injection / suction of a cold jet of isothermal air, interacting with the external environment through two openings arranged in the middle of the left and right vertical walls. The remaining portions of the left vertical wall are subjected to a constant heat flux, while, the remaining walls of the cavity are perfectly insulated. The combined effects of the basic parameters namely the Reynolds number, 20≤Re≤3000, the walls emissivity, 0≤ε ≤ 0.85, and the imposed external flow mode (injection or suction) on the flow characteristics and heat transfer are examined. The results revealed that, for both modes of ventilation, the contribution of radiation to the total heat transfer is significant even for a predominant forced convection regime particularly for high values of wall emissivity. [ABSTRACT FROM AUTHOR]