Problem 3-Diffusion of components (rdif2)

This problem examines diffusion of several solutes (air, benzene, and n-decane) in single phase water. It is the third sample problem in TOUGH3/TMVOC. A 1-D grid of 20 blocks is initialized in single-phase aqueous conditions, with no solutes present. Boundary conditions provided by an inactive (large volume) grid block “ina 1” include step changes of 1.e-7, 1.e-8, and 1.e-6, respectively, for mole fractions of benzene, n-decane, and air. Also, there is a 1 °C change of temperature at the boundary. All diffusivities are specified as $-1.0e^{-6}m^2/s$, where the “-” sign serves as a switch to suppress tortuosity effects (see Equation 4-11, for negative diffusive numbers, let $\tau_0 \tau_\beta=S_\beta$ ). Diffusivities will be taken to be $1.0e^{-6}m^2/s$ for all mass components, and thermal parameters were chosen in such a way that thermal diffusivity Θ = K/ρC also has the same value. Advective processes are suppressed by setting permeabilities to zero. For the same step change in the diffusing quantity (temperature for thermal diffusion, mole fractions for mass diffusion) at the boundary, all diffusive profiles should then be identical. The step changes imposed here differ by powers of 10, and apart from these factors the simulated diffusive profiles are seen to be identical. The FOXM (default value for fraction of organic carbon in soil) for BENZENE has a value 0.001 in the original input, which describes the absorption of BENZENE onto the rocks. It does not take effect on TOUGH3 simulation, but is accounted in TOUGH4. To get the identical results as TOUGH3 simulation, FOXM must be set to be 0 in TOUGH4 simulation.

Input Files: INFILE

Output Files: output files