Intensification of heat exchange in flow of anomalously viscous media in an annular channel with helical ribbing

Abstract

This paper investigates helical ribbing when an anomalously viscous liquid flows through an annular channel. Experiments were carried out on a test stand whose working section was a steel pipe 0.9 m long with inner diameter 0.073 m with a concentrically mounted pipe. As anomalously viscous model liquids the authors used 2.5 and 5% aqueous solutions of sodium carboxyl methyl cellulose (NaCMC) and the thermophysical characteristics of the model liquids were determined. The results of the experiments show that the heat transfer coefficient increases abruptly with increasing effective viscosity of the liquid. It can be seen from a comparison of the data with the results of experiments with model liquids that the effect attained with helical ribbing in anomalously viscous liquids is greater than the analogous effect in viscous media.