Numerical studies of mixing of ellipsoidal particles in a bladed mixer

This paper presents a numerical study of mixing of ellipsoidal particles in a bladed mixer by means of the discrete element method. A wide range of aspect ratios of ellipsoids and sliding friction coefficients are considered. The results show that oblate ellipsoids have worse mixing quality and a lower mixing rate compared with spheres and prolate ellipsoids. Generally, spheres mix faster than ellipsoids, and ellipsoids exhibit higher average velocity and friction forces than spheres. With sliding friction increasing, the curves of mixing rate and particle velocities with aspect ratio shift upward, but do not change further when the sliding friction coefficient is larger than 0.5. The blade torque under different conditions is also examined, showing that increasing sliding friction increases the blade torque, but the torque curve with aspect ratio changes from M-shaped to V-shaped, which indicates a significant effect of particle shape and sliding friction on energy consumption.