User's guide of Proceessing Modflow 5.0

40 Processing Modflow
Fig. 2.31 The Dispersion / Chemical Reaction (MOC3D) dialog box.
< To set Strong/Weak Flag
1. Choose MOC3D < Strong/Weak Flag from the Models menu.
2. Move the grid cursor to the cell [25, 15, 1].
3. Press the right mouse button and type 1, then click OK. Note that a strong sink or source is
indicated by the value of 1 in the matrix. When a fluid source is “strong”, new particles are
added to replace old particles as they are advected out of that cell. Where a fluid sink is
“strong”, particles are removed after they enter that cell.
4. Repeat steps 2 and 3 to assign the value 1 to the cells [25, 15, 2] and [25, 15, 3].
5. Choose Leave Editor from the File menu or click the leave editor button .
< To specify the output terms and times
1. Choose MOC3D < Output Control... from the Models menu.
An Output Control (MOC3D) dialog box appears. The options in the dialog box are
grouped under five tabs - Concentration, Velocity, Particle Locations, Disp. Coeff. and
Misc.
2. In the Concentration tab, select the option These data will be printed or saved every
Nth particle moves and enter N = 20.
3. Click OK to accept all other default values and close the Output Control (MOC3D)
dialog box (Fig. 2.32).
2.2.2 Perform Transport Simulation with MOC3D