ON THE PERIODIC CONDITIONS TO SIMULATE MIXED CONVECTION HEAT-TRANSFER IN HORIZONTAL CHANNELS

Mixed convection heat transfer in open-ended channels with discrete heating from below is numerically studied when the convection cells remain attached to Be heating elements. Two approaches are used: in method A, the computation domain covers the whole channel, while in method B, periodic conditions are imposed at the entrance and exit of a computation domain that is one wavelength long. Nu is calculated as functions of Ra (5 X 10(3) less than or equal to Ra less than or equal to 20 X 10(3)) and of Pe (0.1 less than or equal to Pe less than or equal to 2.5). The results from two approaches show that method B can adequately be used to calculate heat transfer.