NATURAL-CONVECTION HEAT-TRANSFER FROM A STAGGERED VERTICAL PLATE ARRAY

An experimental study was performed to evaluate the natural convection heat transfer characteristics of an array of four staggered vertical plates. The thermal input at each plate was the same or differed from plate to plate depending on various heating modes. The effects of the interplate spacing and the plate-to-ambient temperature difference wer e investigated. The experiments were performed in air. Convective inte ractions among the plates were identified by examining the per-plate h eat transfer coefficients and the local heat transfer coefficients alo ng the vertical sides of plates. Local heat transfer results were obta ined by means of the schlieren quantitative technique. Comparison of l ocal heat transfer coefficients along the plate assembly with those of a continuous vertical plate (having the same height) showed enhanceme nts up to a factor of two. Comparison of average heat transfer results with those for a parallel plate channel having the same exchanger siz e showed only little reductions in heat transfer rate, despite a 28 pe rcent reduction in heat transfer area, with enhancements, in terms of specific heat flux, up to 30 percent.