Friction and heat and mass transfer for turbulent pseudoplastic non-newtonian fluid flows in rough pipes

Friction factor and heat and mass transfer coefficient correlations are developed for turbulent pseudoplastic (purely viscous or inelastic) non-Newtonian fluids flowing through rough pipes. A correlation for friction factor which is applicable in the region of transition from the smooth to the fully-rough regime is proposed. It is obtained by adding the two correlations for the limiting situations, i.e. smooth pipes and fully-rough pipes. The predictions of the proposed correlation are compared with published experimental data and other previous correlations. A model for heat and mass transfer is developed on the basis of the Levich three-zone model. It is found that the proposed model is capable of predicting satisfactorily heat and mass transfer coefficients for Newtonian and pseudoplastic non-Newtonian fluid flow in rough pipes.