H215 Estimation of three-dimensional temperature distributions in free convection field around a small heated sphere in water

Abstract

We propose a novel method for estimating three-dimensional temperature distributions of water in a free convection field around a small heated sphere. This method consists of a near-infrared absorption imaging with a wavelength of 1150 nm and inverse Abel transform. Since temperature distributions formed by free convection above a heated sphere can be assumed to be axisymmetric ones, where the axis is in the opposite direction of gravity, the three-dimensional temperature distributions are reconstructed by applying the inverse Abel transform to every absorbance line profile perpendicular to the axis. The reconstructed temperature distributions show the transient process of free convection, indicating the validity of this method.