EXPERIMENTS ON NATURAL-CONVECTION FROM 2 STAGGERED VERTICAL PLATES

The thermal field and the heat transfer characteristics of a system co nsisting of two staggered vertical plates cooled by air in free convec tion were experimentally studied. The parameters investigated included the interplate spacing, the magnitude of the vertical stagger, and th e Rayleigh number based on the overall convective heat flux From each plate. The experiments were performed in air. The schlieren optical te chnique was employed to obtain the thermal field around the plates and the local heat transfer coefficients along the vertical sides of plat es. Staggering was found to markedly affect the local heat transfer ch aracteristics of the facing sides of the plates when the interplate di stance was relatively small. In general, the Nusselt number averaged o n the inner face of the lower plate was enhanced (up to over 40%) comp ared with that for the case of the unstaggered plate channel. Converse ly the mean Nusselt number on the facing side of the upper plate was r educed (up to 15%).