A Laboratory and Numerical Investigation of Solute Transport in Discontinuous Fracture Systems

摘要: The mixing of fluids at fracture intersections was examined, in the laboratory, using fourteen plexiglass models that simulated open fractures with no contact between walls. Twelve contained two fully intersecting fractures. One model but offset (parallel flow model) and one system a total eleven sets fractures, all same aperture. set composed five parallel other six twelve were designed to investigate effects, on mixing, seven angles intersection three apertures. Iodide solution known concentration injected into distilled water another (inlet ports). At each outlet ports iodide discharge volume measured. ratio volumes compared calculate percent intersection. -- Testing, conducted hydraulic gradients, indicated essentially occurred only nominal model. In general found be dependent upon relative size inlet model, similar lack through which fluid moved. A dimensional finite element written simulate transport conservative solute discontinuous, random, system. Mixing numerical based results physical study. Hence allowed take place except due differences apertures Using this algorithm indicates more longitudinal less lateral dispersion takes than when complete is assumed. addition, discontinuous continuous systems. These findings indicate contaminants migrating fractured media, where walls are not contact, will dispersed diluted extent past have predicted hence contaminant discharged biosphere much greater expected.