Mesh quality agglomeration algorithm for the virtual element method applied to discrete fracture networks

We propose a quality-based optimization strategy to reduce the total number ofdegrees of freedom associated with a discrete problem defined over a polygonal tessellationwith the Virtual Element Method. The presented Quality Agglomerationalgorithm relies only on the geometrical properties of the problem polygonal mesh,agglomerating groups of neighboring elements. We test this approach in the contextof fractured porous media, in which the generation of a global conforming mesh ona Discrete Fracture Network leads to a considerable number of unknowns, due tothe presence of highly complex geometries (e.g. thin triangles, large angles, smalledges) and the significant size of the computational domains. We show the efficiencyand the robustness of our approach, applied independently on each fracturefor different network configurations, exploiting the flexibility of the Virtual ElementMethod in handling general polygonal elements.