Dispersion in three-dimensional networks of polygonal fractures is determin
ed by triangulating the network and solving the two-dimensional convection-
diffusion equation in each fracture or by performing random walks. The gene
ral triangulation methodology and the numerical solution are summarized. Th
e influence of the Peclet number, of the fracture density and of the fractu
re shape are systematically studied. Moreover, fracture networks are shown
to belong to the same universality class as bond percolation networks. (C)
2001 American Institute of Physics.