Mechanisms and modeling of particles' chaotic suspension in low‐ Re elliptical stirred tank reactors

Abstract Particle suspension in high‐viscosity fluids is vital in chemical and biochemical processes. Traditional cylindrical stirred tanks often cause particle clustering due to symmetric flow. Inspired by frightened fish shoal scattering, elliptical stirred tanks create asymmetric, varying flow channels to improve suspension. Optical visualization confirmed this feasibility of design. By introducing Shannon entropy ( S ) to quantitatively evaluate suspension performance, the elliptical stirred tank with an aspect ratio ( E ) of 1.5 exhibited optimal performance ( S max = 0.43). Furthermore, discrete particle model with volume of fluid (DPM‐VOF) simulations reproduced this phenomenon, and revealed that cylindrical tanks trap particles via pressure gradients in symmetric segregated zones, creating dynamic equilibrium. Elliptical tanks disrupt these zones, leading to chaotic particle motion. Finally, a semi‐empirical criterion linking E , particle density ( ρ ), and Reynolds number ( Re ) was proposed. These results demonstrate how flow channel design intensifies particle dispersion for industrial use.