Rheology of bubble suspensions using dissipative particle dynamics. Part I: A hard-core DPD particle model for gas bubbles

Abstract

In this paper, the rheology of dilute bubble suspensions is studied using dissipative particle dynamics (DPD). Each gas bubble is modeled by a hard-core DPD particle. The approach addresses the issue of zero-viscosity arising from modeling of a gas bubble by a set of DPD particles. Moreover, it helps to reduce significantly the computational demand due to a much less number of DPD particles required in the simulation. A dissipative layer is created outside the effective region of the hard-core DPD particle to manage the hydrodynamic force acting on it, and different phases can be defined accordingly. The model is further examined in the simulation of dilute bubble suspensions, and measurements on the Newtonian viscosity for the volume fraction less than 15% are consistent with experimental results and results from theoretical models in continuum mechanics at low Ca limit.