Skip to main content
U.S. flag

An official website of the United States government

Development of a pore network simulation model to study nonaqueous phase liquid dissolution

February 1, 2000

A pore network simulation model was developed to investigate the fundamental physics of nonequilibrium nonaqueous phase liquid (NAPL) dissolution. The network model is a lattice of cubic chambers and rectangular tubes that represent pore bodies and pore throats, respectively. Experimental data obtained by Powers [1992] were used to develop and validate the model. To ensure the network model was representative of a real porous medium, the pore size distribution of the network was calibrated by matching simulated and experimental drainage and imbibition capillary pressure‐saturation curves. The predicted network residual styrene blob‐size distribution was nearly identical to the observed distribution. The network model reproduced the observed hydraulic conductivity and produced relative permeability curves that were representative of a poorly consolidated sand. Aqueous‐phase transport was represented by applying the equation for solute flux to the network tubes and solving for solute concentrations in the network chambers. Complete mixing was found to be an appropriate approximation for calculation of chamber concentrations. Mass transfer from NAPL blobs was represented using a corner diffusion model. Predicted results of solute concentration versus Peclet number and of modified Sherwood number versus Peclet number for the network model compare favorably with experimental data for the case in which NAPL blob dissolution was negligible. Predicted results of normalized effluent concentration versus pore volume for the network were similar to the experimental data for the case in which NAPL blob dissolution occurred with time.

Publication Year 2000
Title Development of a pore network simulation model to study nonaqueous phase liquid dissolution
DOI 10.1029/1999WR900301
Authors Leslie A. Dillard, Martin J. Blunt
Publication Type Article
Publication Subtype Journal Article
Series Title Water Resources Research
Index ID 70185213
Record Source USGS Publications Warehouse
USGS Organization Toxic Substances Hydrology Program