دانلود رایگان مقاله روش المان محدود برای شبیه سازی جریان چند سیال با روش تنظیم سطح ذرات

Abstract

The simulation of immiscible two-phase flows on Eulerian meshes requires the use of special techniques to guarantee a sharp definition of the evolving fluid interface. This work describes the combination of two distinct technologies with the goal of improving the accuracy of the target simulations. First of all, a spatial enrichment is employed to improve the approximation properties of the Eulerian mesh. This is done by injecting into the solution space new features to make it able to correctly resolve the solution in the vicinity of the moving interface. Then, the Lagrangian Particle Level Set (PLS) method is employed to keep trace of the evolving solution and to improve the mass conservation properties of the resulting method. While the local enrichment can be understood in the general context of the XFEM, we employ an element-local variant, which allows preserving the matrix graph, and hence highly improving the computational efficiency.

6. Conclusion

We have proposed a local XFEM method to solve two-fluid flow problems. The pressure field is enriched by a discontinuous basis similar to the ones used in the standard XFEM, but condensed at the elemental level. In this way we take advantage of the stability obtained by the XFEM enrichments and at the same time avoid changing the graph of the matrix as the interface moves. No difference has been detected between the results obtained using this method and those obtained with the standard XFEM for two-fluid flow. To overcome the mass loss/gain of the Level Set, the PLS method is coupled with our local XFEM. Several benchmark problems have been solved using tetrahedral meshes. Numerical results compare well with those obtained with standard XFEM using hexahedral meshes.