Natural convection of water-fine particle suspension in a rectangular vessel heated and cooled from opposing vertical walls (effect of initial distribution of particle concentration)

A water fine particle suspension with a uniform initial temperature and various initial concentration distributions in a rectangular vessel was heated from a vertical wall and cooled from the opposing vertical wall. The particle made of SiO₂ had a narrow size distribution (mean diameter of 2.96 μm standard deviation of 0.023 μm). In order to observe'phenomena of the natural convection, the temperature distribution, local particle concentration of the suspension and position of first interface were measured under various temperature differences between the opposing vertical walls. To make the influence of initial particle concentration on the phenomena clear, natural convection of suspension with three patterns of concentration, i.e. a naturally or artificially formed gradient, or non-gradient, was investigated. The pattern of formation of layers was classified by Grashof number. Moreover, to make the influence of initial depth of suspension clear, the suspensions with three initial depths, 50, 100 or 160 mm, were examined.