rho_w rho_water Density, wetting fluid mu_w mu_water Dynamic viscosity, wetting fluid rho_nw rho_air Density, non-wetting fluid mu_nw mu_air Dynamic viscosity, non-wetting fluid alpha 1.89[1/m] Van Genuchten alpha parameter L 0.5 Van Genuchten L parameter N 2.811 Van Genuchten N parameter, air-water M 1-1/N Van Genuchten M parameter kap_su 2480[mD] Permeability, upper layer theta_ru 0.021 Residual volume fraction, upper layer sigma 1 Ratio between interfacial tensions