Natural Convection Heat Transfer From a Staggered Vertical Plate Array

Abstract

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 were investigated. The experiments were performed in air. Convective interactions among the plates were identified by examining the per-plate heat transfer coefficients and the local heat transfer coefficients along the vertical sides of plates. Local heat transfer results were obtained by means of the schlieren quantitative technique. Comparison of local heat transfer coefficients along the plate assembly with those of a continuous vertical plate (having the same height) showed enhancements up to a factor of two. Comparison of average heat transfer results with those for a parallel plate channel having the same exchanger size showed only little reductions in heat transfer rate, despite a 28 percent reduction in heat transfer area, with enhancements, in terms of specific heat flux, up to 30 percent.