A review of smoothed particle hydrodynamics

Smoothed particle hydrodynamics (SPH) is an evolving computational fluid dynamics (CFD) method. With time, it illustrates a great extent of its capabilities to be considered a practical numerical tool for modeling fluid flow in porous media. It is a free mesh particle-based method benefiting from a Lagrangian nature. This feature makes it a suitable candidate for treating the fluid flow within complex geometries on a mesoscale. A sequential approach is used in the various modifications of SPH. Thereby, the preparation time of models in SPH will be less than those made by using grid-based models. This method offers attractive privileges for dealing with moving boundaries and acquiring the time history of the field variables. In this paper, the basic concepts behind SPH are first introduced. Subsequently, the various discretization approaches and considerations for SPH are reviewed. Its application in the presence of solid boundaries and multiphase contacts is then discussed. Following that, the implementation of inflow/outflow boundaries and miscibility conditions are explored. The considerations for thermal effects and its application in porous media are also presented. The techniques for simulating different fluid types and shortcomings within SPH are eventually described. It is shown that SPH has a significant potential for modeling the fluid behavior on mesoscale although it is computationally expensive. The approximation of second- and higher-order derivatives by using SPH could become erroneous. The stability and consistency of SPH vary from one case to another. It implies that each problem requires a particular modification of SPH. There is still no unified version of SPH.