Hi, let me quote from the FEFLOW help below.
Best regards,
Peter
Density Ratio
Unit: [1]
Default value: 0
The density ratio ? describes the ratio between maximum and minimum density in a density-dependent transport model. It is defined as the density difference in the model divided by the density at reference concentration/temperature.
? = (?max-?0)/?0
It relates concentrations in the model to density differences. By default, FEFLOW assumes ?max to be the density at maximum concentration in initial or boundary conditions and ?0 as the density at a concentration of 0 mg/l.
By default, FEFLOW uses one single Density Ratio for the sum of all concentrations in multi-species simulations. By applying the corresponding setting in Transport Settings in the Problem Settings dialog the density ratio can be specified separately for each single species. In this case, the parameter shows up separately for each species.
Density ratio has to be 0 except for density-dependent models.
