Hydrodynamic and energetic study of a non-Newtonian fluid with a flexible and transformable blade anchor.

Mixing and agitation processes are essential in many industries for the homogenization of simple and complex fluids. However, for non-Newtonian fluids, which may thin or thicken under shear stress, specific challenges arise. In this context, researchers have used standard anchor agitators to scrape the walls of the tanks, primarily generating tangential flow. In this context, researchers have used standard anchor stirrers to scrape the walls of the tank, primarily generating a tangential flow. Although this method is effective, it has certain limitations that motivate the main objective of this study, namely to promote both axial flows while maintaining the tangential flow. This research focuses on the numerical modeling of laminar flow in a mechanically agitated tank containing a shear-thinning non-Newtonian fluid. It examines the impact of the fluid's behavior index, the Reynolds number, as well as various stirrer configurations, including a standard anchor and a flexible blade anchor, to optimize mixing. An innovative agitator design has introduced unique adaptability with a single design modification, enabling transitions between axial flow, which promotes better homogeneity and tangential flow, suited for standard operations. This versatility has proven particularly beneficial for complex fluids with variable rheological properties. The differential equations governing these physical phenomena, including the continuity, momentum and energy equations, are solved using the finite element method. The main results showed that the new flexible blade anchor configuration enhances axial velocity and reduces dead zones at the bottom of the tanks while maintaining an overall tangential flow. Additionally, this configuration provides a significant benefit in terms of energy consumption. Indeed, this new configuration with the largest inclination angle achieved the best results, reducing power requirements by up to 50% under moderate operating conditions. These results highlight the optimization of mixing processes, improving not only the efficiency and quality of the agitation system but also reducing the energy consumption. [ABSTRACT FROM AUTHOR]