Determination of Thermo-physical Properties of Non-Newtonian Fluids Using a Coaxial Cylindrical Cell

Abstract

In this study the thermal conductivity and the volumetric heat capacity of non-Newtonian fluids are investigated. These fluids find many applications in chemical, medical and food industries. They mostly have viscoelastic behavior and generally differ from Newtonian fluids. Two non-Newtonian fluids, solutions of xanthan and carboxy methyl cellulose in water with various concentrations have been prepared and investigated. The apparatus developed has been based on two coaxial cylinder concept for measurement of thermal conductivity and volumetric heat capacity. The thermal conductivity measurement was done from steady state condition data while the volumetric heat capacity was determined from unsteady state experiments. Influence of temperature in the range of 25-80 degrees centigrade and concentration up to 20% has been studied and experimental curves are obtained for both solutions. Based on the data gathered, the empirical correlations obtained, expresses thermal conductivity and volumetric heat capacity as a function of temperature and concentration.