Dual virtual element method for discrete fractures networks
For researchers simulating fluid flow in impervious rock matrices, this work offers a more flexible and simplified discretization approach for discrete fracture networks.
This paper presents two models for computing pressure and Darcy velocity in discrete fracture networks, using a mixed virtual finite element method that handles arbitrary grid shapes, simplifying flow discretization and accelerating computation via algebraic multigrid coarsening. Numerical experiments validate the method's performance.
Discrete fracture networks is a key ingredient in the simulation of physical processes which involve fluid flow in the underground, when the surrounding rock matrix is considered impervious. In this paper we present two different models to compute the pressure field and Darcy velocity in the system. The first allows a normal flow out of a fracture at the intersections, while the second grants also a tangential flow along the intersections. For the numerical discretization, we use the mixed virtual finite element method as it is known to handle grid elements of, almost, any arbitrary shape. The flexibility of the discretization allows us to loosen the requirements on grid construction, and thus significantly simplify the flow discretization compared to traditional discrete fracture network models. A coarsening algorithm, from the algebraic multigrid literature, is also considered to further speed up the computation. The performance of the method is validated by numerical experiments.