Mesh-free particle continuum-based modeling of complex geophysical flows

Abstract:

Complex geophysical flows such as tsunamis, water floods, and avalanche/debris flows, wave atmosphere interaction and violent river flow are the multiphysics flows characterized by large interfacial deformation and fragmentations and frequent topology change in various spatial and temporal scales. Dealing with such characteristics is still beyond the capabilities of many conventional mesh-based Eulerian numerical methods. Mesh-free particle (Lagrangian) numerical methods, such as Moving Particle Semi-implicit (MPS) and Smoothed particle hydrodynamics (SPH), which have been developed for continuum mechanics, offer a unique opportunity to deal with such complexities. This research presents a mesh-free particle method for complex multi‐physics geophysical flows, based on a quasi incompressible MPS-based formulation for turbulent liquid, solid and gas multiphase systems. In combination with the various constitutive relations it is capable of dealing with the non-Newtonian behaviors in geophysical flows (e.g. for case of granular flows). The capabilities of proposed numerical method are evaluated and demonstrated for a series of computationally demanding examples including submarine landslide (and resulting tsunami wave), river flow/ice dynamics, and wave-air interaction. The capabilities of the model in accurate prediction of flow characteristics such as interfacial deformation, velocity/pressure fields, turbulence and mixing processes are demonstrated. Results of this study not only evaluates the capabilities of mesh-free particle methods for complex geophysical flows, but only provides a reliable tool for in deep analysis of mechanisms and processes involved in such flow systems.