Reproducing hydrodynamics and elastic objects: A hybrid mesh-free model framework for dynamic multi-phase flows

Reproducing Hydrodynamics and Elastic Objects (RHEO) is a new meshfree modeling framework for simulating complex multi-phase flows of fluids and solids. RHEO is implemented within the open-source Large-Scale Atomic/Molecular Massively Parallel Simulator particle dynamics code and couples a reproducing kernel smoothed particle hydrodynamics scheme for modeling fluid flow and heat transfer with a bonded particle model for modeling breakable elastic bodies. The resulting scheme provides a robust framework for simulating multi-phase material systems with complex and evolving boundaries and interfaces. RHEO collects many advanced mesh-free modeling features into a centralized, modular, and easily extensible package, including heat transport, reversible melting and solidification, particle distribution regularization, and user adjustable kernel accuracy. We report comprehensive tests of RHEO's accuracy and convergence for common benchmark flows of bulk fluids, boundary driven flows, and complex fluid/solid systems. A series of multi-phase systems are highlighted, including a bouncing water balloon, the fracture and flow of a brittle egg, melting of a free-standing solid beam, and conductive cooling and solidification of an extruded polymer during 3D printing.