Free convective heat transfer and criterion of onset of free convection in a horizontal melt layer of ice heated by upper rigid surface

An experimental and analytical investigation pertaining to the effect of density inversion of water on the free convective heat transfer and the onset of free convection in a horizontal melt layer of ice heated by upper rigid surface is carried out. Temperatures of the upper surface are varied from 1°C to 15°C, with Rayleigh number ranging from 2 × 10² to 1 × 10⁵. From the present study, it can be demonstrated both experimentally and analytically that the density inversion of water plays an influential role in such a melt layer and the onset of free convection and the free convective heat transfer are considerably affected by the temperature of upper rigid surface T₂, in the case of T₂ ≤ 8° C, unlike the results obtained for common fluids without density inversion.