Simulating Kelvin–Helmholtz instability using dissipative particle dynamics

Abstract

Kelvin–Helmholtz (KH) instability is simulated using dissipative particle dynamics (DPD) at the mesoscopic particle level. To model two-phase flow, the ‘color’ repulsion model is introduced to describe binary fluids according to the Rothman–Keller method. The simulated results are compared with similar experiment and simulation using other techniques, and the work concludes that DPD is a promising method for simulating these systems. Furthermore, through the model and numerical simulation, the effects of intermiscibility, temperature, magnitude of velocity difference, and density ratio on the KH instability are investigated, respectively. It is shown that the poor intermiscibility reduces the mixing of two fluids and weakens the eddy currents. It is also found that as the temperature increases, the turbulence feature, i.e. plume-like structures, is more obvious. It is also revealed that as the initial horizontal velocity difference increases, the interface rolls up faster and higher. And it is also observed that as the density ratio increases, the KH instability becomes more suppressed.