Friction factor estimation for turbulent flow of Herschel-Bulkley and power law fluids in pipes

Abstract

Determining the appropriate friction factor value for calculating the frictional pressure loss of non-Newtonian fluids in a pipe is a critical task. This study aims to obtain an explicit friction factor correlation to accurately calculate the pressure losses for turbulent flow of yield pseudoplastic fluids in both smooth and rough pipes. A series of experiments are carried out with carboxymethyl cellulose (CMC) solutions using pipes of three different relative roughness. The Herschel-Bulkley model is found to be the most appropriate model to describe the yield pseudoplastic behavior of the CMC solutions used in this study. Based on the experimental friction pressure data obtained from the Izmir Katip Çelebi University flow loop, an explicit correlation is developed here. The new friction factor equation is compared with not only experiments in this study, but also experimental data presented by Okafor and Evers (1992), Subramanian (1995) and Vjargah et al. (2017). Results show that the proposed friction factor correlation is more consistent and better in agreement with experimental data than existing correlations in the literature. • This is the first study to experimentally investigate the turbulent flow of yield-pseudoplastic fluids in rough pipes. • A new explicit friction factor correlation for determining the pressure losses of non-Newtonian fluids accurately in rough and smooth pipes is proposed. • Experiments are carried out with various CMC solutions using pipes of three different relative roughness. • The Herschel-Bulkley model are found to be the most appropriate model to describe the yield pseudoplastic behavior of the CMC solutions. • The proposed friction factor correlation is more consistent and better in agreement with experimental data than existing correlations in the literature.