Using discrete particles as a natural solver in simulating multiple-scale phenomena

We propose here the usage of different discrete particle methods for simulating both mesoscopic and macroscopic phenomena with hierarchical structures. Results of large-scale MD simulations of the Rayleigh-Taylor instability are shown and discussed. Using about one million Lennard-Jones particles, we have simulated particle fluid environments with a length scale of about 0.5 mum. For encompassing greater length and time scales, either more complex particle method or simplified MD model must be used. In the first case, we study dissipative particle dynamics (DPD) in modeling complex multi-component fluids flows, e.g., bubble formation, fluid flows in porous media, mixing driven by sedimentation. We also demonstrate how the particle method can be utilized for simulating a flexible surface with multiple scales present. We emphasize that the inherent parallelism of the MD method makes this approach a powerful natural solver of a wide variety of physical phenomena with multiple scales.