NATURAL-CONVECTION HEAT-TRANSFER IN STAGGERED VERTICAL CHANNELS

Numerical solutions are obtained for both discrete plate array and parallel plate arrays by solving mass, momentum and energy equations, to determine whether a staggered array of discrete vertical plates yields an enhancement in heat transfer as compared to an array of continuous parallel vertical plates in natural convection. The comparison is made for an equal heat transfer surface area in both cases. It is found that the use of discrete plates gives rise to enhancement in heat transfer when the parameter (D(h)/H)Ra > 600; it is also found that the extent of enhancement is increased at high heat fluxes, larger transverse spacings and for numerous shorter plates. It is also found that the enhancement is restricted to only low system heights, vertical channels giving higher heat transfer rates at larger heights. For the parameter ranges investigated, the heat transfer, relative to the parallel plate array is enhanced by a factor of 3.