Abstract
Laboratory-scale experiments on simplified heterogeneous porous media were conducted in a 100 × 100 × 3 cm sandbox with small blocks of fine or coarse sand. The use of visualization of dye solute and the measurement of NaCl concentration were applied to transitional estimates in longitudinal and transverse dispersivities caused by the presence of heterogeneities. Results showed a larger longitudinal dispersivity in the flow field with fine blocks than that in the flow field with coarse blocks while a continuous decrease in transverse dispersivity was shown despite of the heterogeneity. Laboratory study was extended by a random walk particle tracking and spatio-temporal moments to reflect experimental conditions, demonstrating a good agreement between the experimental and numerical results. Numerical simulations also exhibited that the transverse dispersivity depends on the magnitude of the initial solute distribution.
