Heat transfer of natural convection from a horizontal row of vertical heated plates

Abstract

Natural convective heat transfer from a horizontal row of heated vertical plates to air has been investigated experimentally. The average Nusselt numbers NuL of the plates were measured by varying the plate height L, the gap between plates G and the total number N of the plates contained in the row as, L=50 & 100mm, G=5.2-50.8mm and N=2-10, respectively. The result depicted that the Nusselt numbers for the fixed plate height and gap increase first with increasing the number of plates from N=2 to 7, while they show almost identical values with further increase in N. The latter Nusselt numbers were, then, rearranged with non-dimensional parameters to obtain heat transfer correlation for the rows having large numbers of plates. It was found that their Nusselt numbers NuG are well correlated with the parameter [RaG (G/L)], where NuG and RaG stand for the Nusselt and the Rayleigh numbers based on the gap G. Moreover, the optimum gaps (G/L) to make the Nusselt numbers maximum were discussed from the proposed heat transfer correlation.

Keywords

• natural convection
• heat transfer
• vertical plates
• horizontal rows
• plate fin
• heat exchangers