Abstract
A numerical analysis of unsteady behavior of particle aggregation/dispersion was performed in a non-uniform shear flow in a cylinder with a rotating elliptical rotor. In this model, it was considered that an aggregation/dispersion rate depends on Brownian coagulation, shear coagulation and shear breakup. Immersed boundary method was used to calculate a flow with rotating rotor. The diameter of the cylinder was 38 mm. The major and minor axes of the elliptical rotor were 32 and 26.6 mm. The rotor was rotated at 20 RPM. The diameter of particles and the viscosity of disperse media were 2.5 ?m and 195 Pa s. As a result, the cluster was broken by applying shear and the size of cluster decreased with time. The particle dispersion behavior varies with local position. The mean cluster size took a minimum value right after the major axis of the rotor passed. Then the mean cluster size increased again.
