Lattice Boltzmann simulations of complex fluids: viscoelastic effects under oscillatory shear

We incorporate viscous coupling between components into a numerical model of fluid mixtures. This leads to a memory effect and a frequency-dependent response to applied perturbations. For example, when oscillatory shear is applied to one of the fluid components the viscous drag results in phase segregation if the components have sufficiently different viscosities. Such a situation could occur in dilute polymer solutions where the viscosity is strongly concentration dependent and we present results both for this case and for a symmetric binary fluid mixture.