Effect of buoyancy on the free surface flow past a permeable bed

Abstract

Laminar steady free surface flow having one permeable bounding wall is investigated in the presence of buoyancy force. The experimental results of Rajasekhara [1] were found to be in good agreement with our theoretical results based on a model which admits slip-velocity at the porous material. The effect of buoyancy force is to increase the velocity distribution in the case of greater heat addition (N_o>0) and to decrease it by a greater cooling (N_o<0). As a result, the mass flow rate increases and the friction factor decreases for N_o>0 and the opposite is true for N_o<0. We further find that the effect of buoyancy force on the temperature distribution is to increase its magnitude. In particular, we find that the rate of heat transfer at its nominal surface is increased in the case of heating (N_o>0) of flow.