Numerical simulation on the mixing behavior of double-wave screw under speed sinusoidal pulsating enhancement induced by differential drive

Abstract A novel speed sinusoidal pulsating system is designed by applying differential drive, which is loaded on the plasticizing screw in an extruder or in an injection molding machine. With the CFD software ANSYS POLYFLOW 19.2, this paper builds simplified physical and mesh models for the double wave screw unit, carries out numerical simulation by using particle tracing manner, and finally analyses comparatively the mixing behavior of the wave screw mixing unit with and without sinusoidal pulsating field. It is found that the mixing screw unit with the superimposed excitation field takes on lower transportation efficiency and a descending melt pressure, while there are different reactions on the various pulsating amplitude and frequency for the max shear rate and mixing index. On the other hand, the introducing pulsating field can strengthen the shear field and gain a higher mixing efficiency. The results are of great importance and reference for improving the plasticizing performance and engineering application of the speed pulsating system.