A splitting scheme for highly dissipative Smoothed Dissipative Particle Dynamics

Smoothed Dissipative Particle Dynamics (SDPD) is a novel coarse-grained mesoscopic method for the simulation of complex fluids representing the effect of microscopic scales by a stochastic process. It has some advantages over more traditional particle-based methods but, on the other hand, shares some problems common to particle-based simulations of microfluidic systems. In particular a prohibitive stability constraint prevents its application for Schmidt numbers of O(103) which is typical for liquids. In the present paper we propose an implicit numerical scheme for SDPD that allows to increase significantly the time-step size, and thus to perform simulations at significantly larger Schmidt numbers than was possible previously. Simulations using the new method show close agreement with reference scheme results for Couette and Poiseuille flow. Benchmark results for temperature control (i.e. recovery of macroscopic temperature) are also presented. The radial distribution function of Preprint submitted to Elsevier 29 September 2009 the mesoscopic model liquid is found to be in agreement with experimental results.