Numerical Investigation of Mixing Performance of a High Viscous Fluid in the Novel Static Mixers with Different Group of Helical Leaves

The flow performance and mixing characteristic of a high-viscosity fluid in static mixers with radial multitwisted and axial twisted tapes were numerically investigated based on Lagrangian tracking method. The chaotic mixing performance was evaluated by the tracer particle distribution maps, extensional efficiency and stretching rate. The fluid in the three twisted leaves (TKSM) and four twisted leaves (FKSM) reached chaotic flow more quickly compared with KSM, and the mixing-element groups arranged in the beginning of the mixers played a main role in improving the dispersive mixing whereas the successive ones mainly maintained the dispersive mixing and improved the distribution performance. In contrast, there were large unmixed zones in the static mixer with DKSM. The results for the G values indicate that the macro-mixing performances in the DKSM are better than those in the KSM. KSM, MSM, and SSM had nearly identical stretching rate which were much higher than RSM for Re<10. With the increase of Re, the mixing performance of MSM decreased first and then increased which was just a little larger than that in RSM with the weakest micro-mixing ability. For a given length of static mixer, a decrease in aspect ratio benefited an increasing stretching rate.