Mapping DPD Simulation Parameters to Physical Parameters

Dissipative particle dynamics (DPD) is an emerging method for simulating problems at mesoscopic time and length scales. Studying the DPD methodology based on the dimensionless numbers and expressing its scales in the terms of physical units can open ways to understand thephysical behavior of the systems and to model practical problems. The aim of this paper is to present a DPD approach that describes the correct hydrodynamic behavior of a two-phase fluids system on a length-scale larger than an atom. To achieve this goal, it is required to reproduce the correct liquid viscosity and surface tension between the two phases in DPD system. The formulation is applied to a stationary drop in a multicomponent and free surface system in a wide range of drop radii (between Nano and Micro scales). DPD fluids showed the correct hydrodynamic behavior and the simulated results were in good agreement with the continuum formulation. Although DPD is a promising method, we have found that it should be used with some considerations. There are some limitations on the maximum and minimum viscosity and surface tension that can be modeled with DPD which are discussed in this paper.

Keywords:

Dissipative Particle Dynamics , MDPD , Scaling , Two-phase fluids , Droplet