PHAST Options

19.The Solution Method options will be left at the default values. Select Model|PHAST Solution Method… Verify that an Iterative solver is selected, Space differencing is 0, Time differencing is 1, and the Tolerance is 1e-10. Click OK to close the dialog box.

20.Next, set the Print Initial options. Select Model|PHAST Print Initial... Check the Steady flow velocities, XYZ heads, and XYZ steady flow velocities checkboxes. Leave the remainder unchanged. Click OK to close the dialog box.

21.Next set the Print Frequency. Select Model|PHAST Print Frequency... Change XYZ chemistry to “50000 years”, HDF chemistry to “2000 years”, and XYZ wells to “2000 years.” (Hint, change the units to "years" first.) Change the rest to “0 default” Check the Save final head in *.head.dat checkbox at the lower left. Click OK to close the dialog box.

22.To set the time control, select Model|PHAST Time Control... and set the Time step length to 2000 and the Ending time to 100000. Click OK to close the dialog box.

23.The last step is to turn off the printing of the chemistry for the bottom layer. To do this, draw a polygon entirely surrounding the grid on the top view of the model. In the Object Properties dialog box, select the Nodes radio button. Set the Name to “Deactivate_Printing.” Check the Set values of enclosed nodes checkbox. Set the Number of Z formulas to One and set Z-coordinate to 0. On the Data Sets tab, check the checkbox for Print_XYZ_Chemistry (under "Required|Output.') and change the formula for it to “0.” Click OK to close the dialog box.

 

It is now possible to export the transport data file as ex4.trans.dat, execute the model and view the results as with the previous examples.