Further development of temperature determination for a heated micron-sizedparticle from forced convection

A novel method for determining temperature of a micron-sized particle from forced convective force has been developed. The force was measured for a si ngle suspended particle in an electrodynamic chamber. Particle heating was achieved by focused CO2 laser radiation. With negligible free convection, a correlation was formulated between the forced convective force and tempera ture-dependent viscosity of the gas, on the basis of the Stokes expression. According to this correlation, the ratio of hot to cold forced convective forces on a particle depends on the gas viscosity, and the particle tempera ture can be attained from this ratio. Particle temperature was determined f or a non-reacting glassy carbon particle of 100 mum and a pyrolyzing polyst yrene particle of 157 mum. It was shown that the developed method is straig htforward and quite accurate with an uncertainty of less than 2.5%, and app licable to both reacting and non-reacting particles. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.