Synergistic interaction of thixotropy and inertia in a C-shaped serpentine channel

Abstract

Thixotropy, a property commonly observed in industrial fluids, significantly influences flow and mixing behavior in micromixers. However, its interaction with fluid inertia remains poorly explored. This study examines the behavior of a thixotropic fluid in a C-shaped serpentine channel, focusing on the complex and poorly understood interaction between thixotropy and inertia. A structure-kinetics model is employed to capture the microstructural changes of the thixotropic fluid. We numerically analyze flow and mixing behavior influenced by the Reynolds and the thixotropy numbers, solving coupled continuity, momentum, and structure evolution equations. Thixotropy has a minimal impact on mixing in the creeping flow regime. In the non-creeping flow regime, however, it enhances rotational flow and mixing by reducing viscosity through structural breakdown and increasing fluid inertia. Our findings demonstrate that in the serpentine channel geometry, thixotropy can enhance mixing performance in shorter channels and with lower energy consumption by interacting synergistically with fluid inertia. This highlights the critical role of rheological properties in the design and operation of micro- and macro-scale mixers, with potential applications in biotechnology, pharmaceuticals, food processing, and manufacturing processes involving thixotropic materials.