User's guide of Proceessing Modflow 5.0

182 Processing Modflow
< To place a group of particles
1. Click the Set particle button .
2 Move the mouse cursor to the active model area. The mouse cursor becomes turns into
crosshairs.
3. Place the crosshairs where you want a corner of the "Set Particle" window.
4. Drag the crosshairs until the window covers the subregion over which particles will be
placed, then release the mouse button.
The Add New Particles box appears (Fig. 4.6). Where NI, NJ and NK are the number of
particles in I, J and K directions, respectively. Using NI, NJ and NK, particles can be placed
either on cell faces or within cells which lie in the "Set Particle" window.These numbers can
range from 0 to 999. In the case shown in Fig. 4.6, 8 particles will be placed within each cell,
3 (=3×1) particles will be placed on each cell face and 15 particles will be placed around
each cell at a distance of 20. The particles will get the color and the retardation factor given
in the Properties tab of this dialog box.
< To place a single particle
1. Click the Set particle button .
2. Change the vertical local coordinate and the particle color (for the definition of the vertical
local coordinate, see equation 4.7).
3. Move the mouse cursor to the desired position and click the right mouse button. A particle
will be placed. Note that this particle will have the retardation factor specified in the
Properties tab of the Add New Particles dialog box. Once particles are placed, their color
and retardation factor cannot be changed any more.
4.2 PMPATH Modeling Environment
Fig. 4.6: The Add New Particles dialog box