Physical reflective boundary conditions applied to smoothed particle hydrodynamics method for solving three-dimensional fluid dynamics problems

Abstract

The mixing of continuum and microscopic laws is a contradiction often existing in the boundary conditions utilised in meshfree particle methods. Boundary techniques employing fictitious (or ghost) particles and artificial forces (defined in the molecular microscopic scale) are still used in SPH simulations and should be avoided. Currently, there is an effort in replacing boundary techniques that mix concepts of different scales by others that respect the continuum laws. This paper aims to present the implementation of the physical reflective boundary conditions (RBC) in Smoothed Particle Hydrodynamics (SPH) method for solving three dimensional (3-D) fluid dynamics problems. In this work, SPH was applied to solve the physical conservation equations for a Newtonian, incompressible, uniform and isothermal fluid. Applications in hydrostatics and hydrodynamics are presented as well as the validation of the results in 3-D domains. Two problems were studied: a still fluid inside an immobile reservoir and dam breaking flow. The results achieved presented a good agreement with the analytical solution and literature data.