Rate-Budget Panel
Balance quantities for fluid, mass and heat flow can be calculated and displayed in the budget panels during or after a simulation run. The Rate Budget panel displays the budget (fluid-flow rate, mass-flow rate, heat-flow rate) at the current simulation time step. The budget process is available for the entire model domain, or for a selection of calculation nodes or elements, defining the Domain of Interest (DOI).
Use Selection as Budget Domain in the
context menu of a stored node or element selection in the 
Selections panel can to be chosen
to make a stored node or element selection available as Domain
of Interest (DOI).
| Symbol | Description |
|---|---|
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Alternatively, the stored
element selection that is currently selected in the |
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Remove one of the available selections with this button. |
The rate budget values shown refer to the selection chosen in the drop-down list. If no stored selections have been added in addition, the entire domain as well as the current node and element selections are available.
The results are shown when the 
Active check box is checked and
FEFLOW is in simulator mode. Separate tabs are shown for Flow,
Mass (possibly different species),
Heat and Age
(possibly different species) according to the Problem Class settings.
The boundary flows are divided in negative flows (out of the model/domain of interest - red) and positive flows (into the model/domain of interest - green) and are shown in bars for the different kinds of boundary conditions and the areal/volumetric sources or sinks:
Flow Budget
|
Budget Component |
Description |
|---|---|
|
Dirichlet Boundary Conditions |
Flow at Hydraulic-head BC nodes |
|
Neumann Boundary Conditions |
Flow at Fluid-flux BC nodes |
|
Cauchy Boundary Conditions |
Flow at Fluid-transfer BC nodes |
|
Wells |
Flow at Well BC nodes and Multilayer Well bottom nodes |
|
Distributed Sink(-)/Source(+) |
Flow due to Source/Sink and In-/Outflow
on Top/Bottom |
|
Storage Capture(-)/Release(+) |
Storage capture (left side, negative) and release from storage (right side, positive): both effects of confined storage related to Specific Storage and unconfined storage related to Drain-/fillable Porosity or Unsaturated Porosity lumped into one value |
|
Internal Transfer |
Only for element selection as domain of interest: model-internal inflow and outflow to/from the domain of interest |
|
Imbalance |
Sum of all the other values, should be close to 0 (residual mass-balance error) |
Mass Transport Budget
|
Budget Component |
Description |
|---|---|
|
Dirichlet Boundary Conditions |
Advective mass
flow at Mass-concentration
BC nodes |
|
Neumann Boundary Conditions |
Advective mass flow at Mass-flux
BC nodes |
|
Cauchy Boundary Conditions |
Advective mass flow at Mass-transfer
BC nodes |
|
Wells |
Advective mass flow at Mass
nodal sink/source BC nodes |
|
Distributed Sink(-)/Source(+) |
Mass flow due to Source/Sink |
|
Storage Capture(-)/Release(+) |
Storage capture (left side, negative) and release from storage (right side, positive) |
|
Internal Transfer |
Only for element selection as domain of interest: model-internal mass inflow and outflow to/from the domain |
|
Imbalance |
Sum of all the other values, should be close to 0 (residual mass-balance error) |
Heat Transport Budget
|
Budget Component |
Description |
|---|---|
|
Dirichlet Boundary Conditions |
Advective heat
flow at Temperature
BC nodes |
|
Neumann Boundary Conditions |
Advective heat flow at Heat-flux
BC nodes |
|
Cauchy Boundary Conditions |
Advective heat flow at Heat-transfer
BC nodes |
|
Wells |
Advective heat flow at Heat
nodal sink/source BC nodes |
|
Distributed Sink(-)/Source(+) |
Heat flow due to Source/Sink, heat flow due to Source/Sink (fluid flow) and In-/Outflow on Top/Bottom in the Convective Form |
|
Storage Capture(-)/Release(+) |
Storage capture (left side, negative)
and release from storage (right side, positive), |
|
Internal Transfer |
Only for element selection as domain of interest: model-internal heat inflow and outflow to/from the domain |
|
Imbalance |
Sum of all the other values, should be close to 0 (residual mass-balance error) |
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The calculation of flows of thermal energy per time requires a unique reference for the temperature. FEFLOW uses the Reference Temperature set on the Transport Settings page of the Problem Settings dialog. This means that for example in case of 9°C warm water flowing into an aquifer of 8°C temperature the heat flow at the inflow boundary is shown as negative if the reference temperature has been set to 10°C. |
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The budget quantities can also be visualized in the Slice View and 3D View windows by visualizing the respective Rate Budget component from the Data panel. |
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In one very specific case the Imbalance does not show the residual mass-balance error: If Arbitrary 1D Feature Elements connect nodes outside the DOI with nodes inside the DOI, the flows through these add to the imbalance, as they are not captured by the Internal Transfer through the DOI boundaries. |
Budget Export
The calculated rate-budget values (Budget Components)
can be exported to a text file (*.txt)
via the context menu on the panel (
Export Current Values).
The format used to display the numbers in the
bars can be changed by using the Number Format entry in the context
menu of the panel.