HEAT-TRANSFER BETWEEN A FLUID-SATURATED POROUS-MEDIUM AND A PERMEABLEWALL WITH FLUID INJECTION OR WITHDRAWAL

The present paper addresses heat and mass transfer between a permeable wall and a fluid-saturated porous medium. To assess the effect of wal l suction or injection on sensible heat transfer, a stagnant film mode l is developed. The model yields a thermal correction factor accountin g for the effect of wall transpiration on heat transfer. In order to a pply this correction factor, neutral (or zero mass transfer) heat tran sfer rates must be specified. In the past, for a large number of pract ical situations heat transfer correlations have been obtained with the boundary layer model, which are summarized here. Subsequently, the de rived correction factor is applied to free, mixed and forced convectio n flows along vertical and horizontal permeable walls embedded in a po rous medium. The predictions of the film model are compared and found to be in good agreement with corresponding results obtained with the b oundary layer model (also provided by the literature). Hence, the film model approach appears to be a compact and adequate description of th e processes considered.