Laminar mixed convection in the entrance region of shrouded arrays of heated rectangular blocks is approximated numerically for large Prandtl number fluids. The problem considered is related to the convective cooling of electronic components mounted on horizontal circuit boards. Two heating conditions are investigated; in case 1, the uniformly heated components are facing upwards and, in case 2, the heated components are facing downwards. Typical fluid streamlines and isotherms, block wall temperature distributions and local Nusselt numbers are presented. It is found that the secondary flow leads to a significant enhancement in heat transfer for cases where the block faces upwards rather than downwards.
Canadian journal of chemical engineering 66(3), pp.361-366