Numerical evaluation of immiscible metallic Zn–Pb binary alloys in shear-induced turbulent flow

This paper presents a numerical investigation of the breakup of Pb metallic drops into a Zn matrix phase in shear-induced turbulent flow. This is the main flow feature in the rheomixing process, which has been successfully developed for casting immiscible metallic engineering alloys. A numerical evaluation by a volume-of-fluid (VOF) method with a turbulence model is presented for the studies of fundamental hydrodynamic mechanisms of immiscible metallic droplets. It is noted that turbulence speeds up the drop breakup process and leads to the formation of spherical droplets. It was found that the deformation and rupture of immiscible metallic drops could be predicted essentially via the capillary number. It was observed that the Pb metallic drops could be more easily broken up in thin viscous fluids and get a more spherical shape in thick viscous turbulent flow. The initial breakup scale factors (IBSF) Kr, KL and Krmax are introduced for measuring the breakup evolution for the parametric study.