UNSTABLE CONVECTION IN VE.RTICAL CHANNELS WITH HEATING FROM BELOW/INCLUDING EFFECTS OF HEAT SOURCES AND FRICTIONAL HEATING

摘要

The effects of heat sources am$ frictiona1 beating on the laminar fully developed channel flow subject to a body force between two parallel plates oriented in the direction of the body force are analyzed. Solutions are obtained for combined forced- and natural-convection flows for the cases in which the wall temperature variations are linear and (l) the wall temperatures are specified, (2) the walls are both insulated, and (3) the net mass flow in the channel is zero. These solutions depend on the Rayleigh number which was previously found to be the factor determining the stability and type of flow for horizontal and vertical layers of fluids heated from below but without heat sources or fractional heating. Similar stability characteristics are displayed in the present problem, and the heat sources affect the flows only in a quantitative manner.