Numerical experiments of flow and transport in a variable-aperture fracture subject to effective normal stresses.

This paper investigates numerically characteristics of the fluid flow and solute transport in variable-aperture fractures under effective normal stress conditions. In order to represent a nonlinear relationship between the supported effective normal stress and the fracture aperture, a simple mechanical model is combined with a local flow model. The solute transport is simulated by using the random walk particle following algorithm. Obtained numerical results indicate that the flow and transport are significantly affected by the geometry of aperture distribution varying according to the applied effective normal stress (sn). The spatial correlation length also has influence on the flow and transport at higher values of sn . The most efficient path for the flow does not remain the same with sn . However, the path keeps almost the same form at higher values of sn . The particles displace only along channels reduced by contact areas increasing with s n and their spatial dispersion thus becomes constant.