Transport water flow

[Nata]

Hello everyone! I am new to phreeqc. I am trying to simulate the flow of water in a well, knowing its composition (the case of a non-porous medium is considered). As I understand it, for this you need to use the TRANSPORT block. I read about it in the guide. Did I understand correctly that if we do not specify porosity, then by default we model a NON-porous medium? I also had a question about taking into account the temperature gradient of this water. Is there a separate block for taking this change into account, or maybe you can help and recommend examples that describe something similar (in example 12 there was a change, but not from point to point of medium)?

[dlparkhurst]

With the TRANSPORT numerical method, the porosity is usually not important. Water, normally about 1 L, is advected from cell to cell, and dispersion is simulated by mixing adjacent cells, sometimes multiple times for large dispersivities.

You can simulate the flow of heat in a column with two TRANSPORT parameters--a thermal retardation factor and a thermal diffusion coefficient. See the manual for more details, but if your gradient is at steady state, I think you can use REACTION_TEMPERATURE data blocks to maintain a constant temperature in each cell.