Research on the Mesoscopic Characteristics of Kelvin–Helmholtz Instability in Polymer Fluids with Dissipative Particle Dynamics

In this paper, the two-dimensional Kelvin–Helmholtz (KH) instability occurring in shear flow of polymer fluids is modeled by dissipative particle dynamics (DPD) method at coarse-grained molecular level. A revised FENE model proposed to properly describe chains. model, elastic repulsion and tension are both considered between adjacent beads, bond length which set as one segment’s equilibrium length. The entanglements chains described with a bead repulsive potential. characteristics such KH fluid can be successfully captured simulations use modified model. numerical results show that waves vortexes grow more slowly than Newtonian case, these become flat, impedes mixing inhibits generation turbulence. effects concentration, chain length, extensibility also investigated regarding evolution instability. It shown two reduces, becomes suppressed concentration increases. much longer elongated interface turns longer. As increases, flattened. Moreover, roll-up process significantly if has sufficiently high extensibility. These observations its properties influence formation coherent structures progress.