SINGLE-PHASE FLOW IN PARTIALLY FISSURED MEDIA

Totally fissured media in which the individual cells are isolated by t he fissure system are effectively described by double porosity models with microstructure. Such models contain the geometry of the individua l cells in the medium and the flux across their interface with the fis sure system which surrounds them. We extend these results to a dual-pe rmeability model which accounts for the secondary flux arising from di rect cell-to-cell diffusion within the solid matrix. Homogenization te chniques are used to construct a new macroscopic model for the flow of a single phase compressible fluid through a partially fissured medium from an exact but highly singular microscopic model, and it is shown that this macroscopic model is mathematically well posed. Preliminary numerical experiments illustrate differences in the behaviour of solut ions to the partially fissured from that of the totally fissured case.