LAMINAR NATURAL-CONVECTION FLOW AND HEAT TRANSFER OFnFLUIDS WITH AND WITHOUT HEAT SOURCES IN CHANNELSnWITH CONSTANT WALL TEMPERATURES

摘要

The natural-convection phenomenon is analyzed and it is found that the flow and heat transfer, in general, not only are functions of the Prandtl and Grashof numbers but also depend on a new dimensionless parameter. If this parameter is not negligibly small, the compression work and frictional heating may appreciably affect this mode of heat transfer.nConsideration is given to the particular case of fully developed natural-convection flow of fluids with and without heat sources between two parallel long plane surfaces the temperatures of which are main¬tained constant but not necessarily equal. These plates are oriented in the direction parallel to the generating body force. Solution of this problem yields detailed information on the velocity and tempera¬ture distributions and heat transfer to be expected for such flows in tall narrow channels, on the effect of heat sources in the fluid, and on the effect of frictional heating on the process. It is found that the frictional heating and the heat sources increase the velocities and temperatures within the channel formed by the two surfaces. Increasing the ratio of the two wall-temperature differences (wall minus outside ambient) also leads to similar results.