PFEM based solvers implemented in the OpenFOAM(R) suite

JUAN M. GIMENEZ; HORACIO J. AGUERRE; SERGIO R. IDELSOHN; NORBERTO M. NIGRO

Conferencia; V International Conference on Particle-Based Methods; 2017

CIMNE

The latest version of the Particle Finite Element Method (PFEM-2) [1] is a numerical method based onthe Lagrangian formulation of the equations which presents advantages in terms of robustness andefficiency over classical Eulerian methodologies especially when convection plays an important role [2].Previous publications demonstrated its ability to achieve solutions with a good compromise betweenaccuracy and efficiency, in both, academic [3,4] and real engineering problems [5] where very complexgeometries and operating conditions require very large computations. This work affords the next stepwhich consists in opening the implementation of this methodology in order to extend the number of usersalong the world.In this context, the suite OpenFOAM® is the platform selected where including the developments. Thisfree open source code is one of three world?s most used CFD softwares and the library is structured suchas resulting simple to develop reliable and efficient computational continuum-mechanics algorithms [6].This selected platform implements the Finite Volume Method (FVM) which discretizes the space in adifferent way from the Finite Element Method (FEM), from which the PFEM-2 is based. This fact makesnecessary the development of FVM-based interpolations and projection operators in order tocommunicate the fields between the background fixed-mesh and the cloud of particles. A deep discussionof these new strategies is included in this work.When stable, monotonous and accurate convective solutions are searched, the High Resolution Schemes(HRS) as TVD and NVD are the native OpenFOAM® best discretization schemes among the availables.However, in these schemes is necessary to previously know the features of the solution due to theircompressive/non-compressive behavior. In this context, employing particles for convection, as inPFEM-2, gives several advantages as enlarging time-step without distorting any kind of solution shape[7]. Another important advantage of the Lagrangian approach is that convection becomes independent ofmesh quality avoiding typical FVM induced errors as skewness. Benchmark tests are proposed to verifythese facts: accuracy of results is evaluated and special focus on computing times and parallel efficiencyis done in order to demonstrate the improvement that offers PFEM-2 over the currently available CFDtools.