AN ANALYTICAL STUDY OF HEAT AND MASS-TRANSFER THROUGH A PARALLEL-PLATE CHANNEL WITH RECYCLE

The effects of recycle at the ends on the heat and mass transfer throu gh a parallel-plate channel with;uniform wall temperature are studied by an orthogonal expansion technique. The heat and mass transfer probl em is solved for fully developed laminar velocity profiles in a parall el-plate channel with ignoring axial conduction, and with fluid proper ties which are temperature independent. Analytical results show that r ecycle can enhance the heat transfer rate for high Graetz numbers comp ared with that in an open conduit (without an impermeable plate insert ed and without recycle). The preheating and residence time are the two effects which are in domination of the heat transfer behavior. (C) 19 98 Elsevier Science Ltd. All rights reserved.