On the influence of liquid elasticity on mixing in a vessel agitated by a two-bladed impeller

The experimental study of the velocity field and power consumption has been conducted in a mixing vessel equipped with a two-bladed impeller for a viscoelastic fluid and Newtonian and non-Newtonian inelastic fluids for comparison. The results are interpreted in the light of a numerical simulation using a finite element method for an Oldroyd B fluid. Both numerically and experimentally a significant influence of elasticity is found for an effective Reynolds number greater than a threshold value 5 to 7. Above this value, the power number is increased and the velocity field deeply modified. This behavior is mainly related to elasticity of the fluid.