Non-Newtonian behaviour of the gyroid mesophase: A lattice-Boltzmann study

We use a lattice-Boltzmann (LB) kinetic scheme for modelling amphiphilic mixtures to impose Couette flow on self-assembled gyroid mesophase. We report evidence of non-Newtonian behaviour (“shear thinning”) and we show that the particular lack of inversion symmetry which characterizes the gyroid unit cell does not quantitatively affect the flow dynamics beyond a certain predictable shear velocity threshold. This purely kinetic approach is of general importance for the modelling and simulation of complex fluid flows in situations when rheological properties cannot be predicted a priori.