Structure of Flows in Viscoplastic Fluids Mixing

The laminar isothermal mixing of a viscoplastic fluid is considered in the absence of any free surface and when the material can be modelled using a Bingham constitutive equation. The material is mixed by a rotating cylindrical tank and a fixed anchor impeller. A two-dimensional numerical simulation is performed with a finite elements method. The effects of viscoplasticity and inertia are related to an Oldroyd (Od) and to a Reynolds (Re) number. Stream lines, vortices, yield surfaces and power consumption are shown and analysed depending on the value of Od and Re parameters.