DHIJWASv Software FEFLOW 6.1

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To get familiar with the settings for transport simulations
load the model simulation.fem.
Open the Problem Settings dialog via the Edit
menu and start on the Problem Class page. Saturated
conditions are assumed and transport of Mass (dissolved
constituents) is included. The state for both
flow and transport is set to Transient.
In mass-transport simulations, the Problem Settings
dialog contains two additional pages: In General settings
on the Transport Settings page, we can choose
between the Convective and the Divergence
form of the transport equation and change the settings
for the calculation of fluid viscosity and density. Additionally,
the Reference concentration for the masstransport
calculation, and the Reference temperature
for heat-transport problems are specified here.
Switch to the Chemical Species page. Here, additional
species that are associated with the fluid or the
solid phase can be defined if the model requires more
than one species. To add or remove species from the
list, the Add species or Delete current species
tools can be used.
Proceed to the Numerical Parameters page. On this
page, the settings for the Error tolerance and for the
computation of mass matrices are located. Additionally,
different upwinding techniques, e.g., Full
upwinding or Shock capturing can be selected to
stabilize the transport calculation. As we can see, for
the current model the default option No upwinding
(Galerkin-FEM) is set. Click Cancel to leave the
dialog without any changes.
Notice how the Data panel has changed compared
to a flow simulation: The Process Variables,
Boundary Conditions and Material Properties trees
now each contain an additional branch for mass transport
(see Figure 7.7).
Figure 7.7 Data panel with mass-transport parameters.
In models with multiple chemical species, a separate
branch is created for each species so that initial
concentrations, boundary conditions and material properties
can be defined separately for each species.
Start the simulation with a click on Start in the
Simulation toolbar. The Rate-Budget and the
Period-Budget panels now have two tabs, one for
Fluid and one for Mass. To monitor the mass budget
during the simulation, click on the tab Mass in both
panels and set the checkmark in front of Active. If a
model contains multiple species, the panels contain a
separate tab for each species.
The Content panel also contains additional
entries for transport. To evaluate the amount of dissolved
mass in the model, start the content calculation