Impact of External Surroundings on Natural Convection in a Vertical Channel Asymmetrically Heated

Abstract

Abstract. This paper reports a numerical study of natural convection problem between vertical plates with asymmetric heating. Influence of perturbation conditions outside of the channel on flow structure and on the heat transfer rate are investigated. The effect of temperature consists of considering a gradient of temperature between the bottom and top of the channel in order to obtain a thermal stratification. The effect of surface radiation on the laminar air flow with a thermal stratification is investigated by considering temperature of grey bodies. Results show that these weak perturbations outside the channel are a real influence on flow and that the influence of thermal stratification is more important than surface radiation. Numerical simulations have been carried out at modified Rayleigh number Ra=5.10 5 (laminar regime) and with Prandtl number Pr=0.71.

Impact of external temperature distribution on the convective mass flow rate in a vertical channel – A theoretical and experimental study

“…He showed that once the thermal stratification develops and reaches the top of the channel, the induced mass flow rate decreases. More recently Ramalingom and Bastide [29] also numerically modelled a uniformly heated channel introducing a temperature difference in the ambient fluid between the inlet and the outlet corresponding to a stable stratification in the ambient fluid. The results show as well a decrease in the induced mass flow rate.…”