Numerical simulations of two-phase non-Newtonian fluids
Tid: Må 2019-08-26 kl 15.00
Plats: Faxén, Strömningsfysik labb, TR8, Mekanik
Medverkande: Outi Tammisola, Institutionen för Mekanik
Complex fluids’ transport and flow over surfaces governs the production of many Swedish and global industries, along with natural hazards. Inability to predict and control such flows leads to technological barriers for novel applications, just to name one example, 3D printing with ground-breaking potential from tissue engineering to sustainable foods. Traditional process industries waste energy when trying to improve mixing and prevent clogging (10% of the energy consumption of the world is estimated to come from handling of granular materials, of which complex fluids are an important part). These processes are extremely challenging to control, because theories for complex fluid flows have large gaps, in particular for so-called yield-stress fluids that flow when sheared strongly, but are solids otherwise. The first part of this lecture will give a physical understanding into common properties of complex fluids, a shear-dependent viscosity, elasticity and yield-stress, and mentions specific challenges when incorporating them in numerical simulations. The second part of the lecture will rely on latest research results to explain how the presence of a non-Newtonian fluid profoundly changes the dynamics of laminar and turbulent flows, and how it influences the movement of droplets and bubbles that often are contained in many real-life complex fluids.