MASSIVELY-PARALLEL NONEQUILIBRIUM BROWNIAN DYNAMICS SIMULATIONS FOR COMPLEX FLUIDS - THE RHEOLOGY OF BROWNIAN SUSPENSIONS

The complex theology of colloidal suspensions under shear flows is a d irect consequence of shear-induced microstructural changes. Non-equili brium Brownian Dynamics (NEED) simulations can be used to study and un derstand this theology and its relationship to the suspension microstr ucture. However, system size effects can influence the observed theolo gy and structural evolution. In this paper, we describe a data paralle l algorithm for NEED appropriate for a SIMD architecture and apply it to simulate systems of >250,000 Brownian disks under simple shear. The evolution of the shear and normal stesses is explained by detailed ex amination of the shear-induced microstructure. A transition to a strin g phase is seen consistent with experiments and smaller simulations, s howing it not to be an artifact of simulation size effects.