Author:

Keywords:

Science & Technology, Technology, Physical Sciences, Mechanics, Physics, Fluids & Plasmas, Physics, PARTICLE DYNAMICS SIMULATION, MOLECULAR-DYNAMICS, COMPUTER, ALGORITHMS, RHEOLOGY, PACKAGE, MICRORHEOLOGY, EFFICIENT, ESPRESSO, MODEL, Research Foundation Flanders (FWO) Odysseus Program (grant agreement no. G0H9518N), International Fine Particle Research Institute (IFPRI), 01 Mathematical Sciences, 02 Physical Sciences, 09 Engineering, Fluids & Plasmas, 40 Engineering, 49 Mathematical sciences, 51 Physical sciences

Abstract:

Molecular dynamics (MD) simulations represent a powerful investigation tool in the field of soft matter. By using shear flows, one can probe the bulk rheology of complex fluids, also beyond the linear response regime, in a way that imitates laboratory experiments. One solution to impose a shear flow in particle-based simulations is the Lees-Edwards technique which ensures that particles experience shear by imposing rules for motion and interactions across the boundary in the direction of the shear plane. Despite their presentation in 1972, a readily available public implementation of Lees-Edwards boundary conditions has been missing from MD simulation codes. In this article, we present our implementation of the Lees-Edwards technique and discuss the relevant technical choices. We used the ESPResSo software package for Molecular Dynamics simulation of soft matter system, which can be used as a reference for other implementers. We illustrate our implementation using bulk dissipative particle dynamics fluids, compare different viscosity measurement techniques, and observe the anomalous diffusion in our samples during continuous and oscillatory shear, in good comparison to theoretical estimates.