Author(s): R. Kaiser; T. Rother; O. Kolditz
Linked Author(s):
Keywords: Fracture network; Network meshing; Automatic grid adaptation
Abstract: This paper deals with the utilization of automatic grid adaptation (h-adaptive method) on fluid flow processes in fracture networks. The h-adaptive method is used to improve the numerical solutionfor fractured aquifer simulations. As an application, a fault system near Soultz-sous-For\^ets in France is investigated, where a geothermal research site (Hot Dry Rock System) is under development. The finite element program Rockflow-3 has been developed to simulate complex flow and transport processes of one and more fluid phases in subsurface hydrosystems, combining coupled modules with the method of automatic grid adaptation (Kolditz et al. 1998, Kaiser et al. 1998, Habbar et al. 1998, Thorenz 1998). The different flow zones in the fractured aquifer, such as surroundings of sinks and sources, the interaction area between fracture and matrix, and the area between zones of different material parameters are discretized for 3d-problems by an automatically adapted grid. The velocity field can now be modelled with high accuracy for each point of time, and the new grid can be used later for an adaptive tracer and/or heat transport simulation. The numerical solution of the flow equation is based on a semi-discrete finite element method for unstructured grids where the porous rock matrix is discretized by 3dvolumes, fractures by 2d-planes and main pathways within the fractures by 1d-lineelements.
Year: 1999