Experimental and CFD study on the flow mixing characteristics of the new fish-tail bionic static mixer

Static mixers (SM) are widely used for reaction and heat transfer intensification, yet further improvements in mixing efficiency remain highly desirable for fast reactive systems. Accordingly, bionic fishtail-shaped static mixers (FTSM) were proposed and systematically compared with a conventional Kenics static mixer (KSM) for Mg(OH) 2 precipitation using experiments and CFD simulations. The results indicated that FTSM-V generated continuously distributed longitudinal and transverse vortices, which enhanced turbulence intensity and promoted a more continuous decrease in COV along the axial direction. The coefficient of variation (COV) of the FTSM-V decreased to 0.010, which is approximately 30% lower than that of KSM, at z / l = 3.5 and Re = 6000. In KSM, the stepwise rise in product concentration occurs at the junction between the 1# and 2# elements, while it occurs mainly in the upstream region of the 4# element in FTSM-V. The yield using FTSM-V was 13.7% higher than that of KSM. A maximum volumetric specific power dissipation of 520 kWh/m 3 was achieved, representing a 36.2% improvement over non-optimal conditions, at C total = 5.25 mol/L and R = 3. This work provided a novel fishtail-shaped static mixer design, enabling an efficient and scalable strategy for intensifying mixing–reaction coupling in fast reactive systems.