Chapter 40 - Flow of Newtonian and non-Newtonian fluids in an agitated vessel equipped with a non-standard anchor impeller

Abstract

This chapter describes the use of a commercially available fluid dynamic (CFD) software package (FLUENT) to conduct numerical simulation for the flow field of Newtonian and Non-Newtonian viscous fluids in a rounded bottom vessel equipped with an atypical anchor impeller. The reliability of the numerical procedure is demonstrated on the basis of a comparison of the numerical results with experimental data in several ways. The chapter begins with a discussion of different classes of fluids, for which, different classes of fluids—Newtonian, shear-thinning, and yield stress fluids—measured and numerically calculated power consumption are reported. For all the fluids investigated, standard deviation between the calculated and measured data is found inferior to 15%. Following this, for a Newtonian fluid, measurements of tangential velocity fluctuation obtained by Laser-Doppler Velocimeter (LDV) in an area located near the shaft of the mixer are compared to the computational fluid dynamic (CFD) values. Close agreement between the numerical computed CFD values and the LDV tangential velocity data were also obtained. Finally, the flow velocity field computed for non-Newtonian liquids in the vessel are analyzed and briefly compared to those obtained with Newtonian liquid at the same Reynolds number.