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

We incorporate viscous coupling between components into a numerical model o f fluid mixtures. This leads to a memory effect and a frequency-dependent r esponse to applied perturbations. For example, when oscillatory shear is ap plied to one of the fluid components the viscous drag results in phase segr egation if the components have sufficiently different viscosities. Such a s ituation could occur in dilute polymer solutions where the viscosity is str ongly concentration dependent and we present results both for this case and for a symmetric binary fluid mixture.