Natural Convection Heat Transfer in Vertical Parallel Plates with a Closed Lower End : 2nd Report, Experiment

Abstract

An experimental study on natural convection heat transfer in two vertical parallel plates with a closed lower end was performed in air using isothermal plates with heights of 100 and 200 mm, and the results were compared with those of numerical analysis. The Grashof number range in the experiment was about 10⁶ to 10⁸ and the ratio of hot and cold wall temperatures was from 0.4 to 1. In the dimensionless distance of the parallel plates of from 0.1 to 0.3, the temperature of the air between the plates fluctuated considerably over time. The heat transfer coefficients of the plates in the experiment exhibit good agreement with the numerical results when Gr_sS² >__- 10⁶, but when Gr_sS² < 10⁶, they are slightly smaller than the numerical results, at R=1.