Period-Budget Panel

Balance quantities for fluid, mass and heat can be calculated and displayed in the budget panels during or after a simulation run. The Period-Budget panel shows the integrated budget for a time period to be selected. 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
	Alternatively, the stored element selection that is currently selected in the Selections panel can be added to the list of available selections by hitting this button.
	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 For density-dependent flow: buoyancy term in addition
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
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 Convective Form of the transport equation: Dispersive/diffusive mass flow at Hydraulic-head BC nodes Divergence Form of the transport equation: Dispersive/diffusive mass flow at Mass-concentration BC nodes
Neumann Boundray Conditions	Advective mass flow at Mass-flux BC nodes Convective Form of the transport equation: Dispersive/diffusive mass flow at Fluid-flux BC nodes Divergence Form of the transport equation: Dispersive/diffusive mass flow at Mass-flux BC nodes
Cauchy Boundary Conditions	Advective mass flow at Mass-transfer BC nodes Convective Form of the transport equation: Dispersive/diffusive mass flow at Fluid-transfer BC nodes Divergence Form of the transport equation: Dispersive/diffusive mass flow at Mass-transfer BC nodes
Wells	Advective mass flow at Mass nodal sink/source BC nodes Convective Form of the transport equation: Dispersive/diffusive mass flow at Well BC nodes and Multilayer Well bottom nodes Divergence Form of the transport equation: Dispersive/diffusive 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 Convective Form of the transport equation: Dispersive/diffusive heat flow at Hydraulic-head BC nodes Divergence Form of the transport equation: Dispersive/diffusive heat flow at Temperature BC nodes
Neumann Boundary Conditions	Advective heat flow at Heat-flux BC nodes Convective Form of the transport equation: Dispersive/diffusive heat flow at Fluid-flux BC nodes Divergence Form of the transport equation: Dispersive/diffusive heat flow at Heat-flux BC nodes
Cauchy Boundary Conditions	Advective heat flow at Heat-transfer BC nodes Convective Form of the transport equation: Dispersive/diffusive heat flow at Fluid-transfer BC nodes Divergence Form of the transport equation: Dispersive/diffusive heat flow at Heat-transfer BC nodes
Wells	Advective heat flow at Heat nodal sink/source BC nodes Convective Form of the transport equation: Dispersive/diffusive heat flow at Well BC nodes and Multilayer Well bottom nodes Divergence Form of the transport equation: Dispersive/diffusive heat flow at Heat nodal sink/source BC nodes
Distributed Sink(-)/Source(+)	Heat 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 heat inflow and outflow to/from the domain
Imbalance	Sum of all the other values, should be close to 0 (residual mass-balance error)

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.

The budget quantities can also be visualized in the Slice View and 3D View windows by visualizing the respective Period Budget component from the Data panel.

Period

Here, the time period for the cumulative budget is to be defined. Having a full results file (*.dac) loaded, the time period can be chosen as an arbitrary interval within the saved time period. Otherwise (during the simulation run) the temporal integration starts at simulation start and runs until the current time step.

When having loaded a full results (*.dac) file, the ∫...dt button has to be hit to start the budget calculation. Optionally, rate and period budget can be exported to a *.txt file during the calculation by choosing a file name after starting the calculation. Hitting the button starts the calculation and export for all quantities that have Export checked in the Period Budget and Subdomain Boundary Period Budget panels. For each exported quantity, a separate file name has to be chosen.

For use during the simulation run, the calculation should be activated before the simulation is started to integrate sources/sinks occurring from the simulation start to the current time step.

Budget Export

The calculated period-budget values can be exported to a text file (*.txt) via the context menu on the panel ( Export Current Values) after the budget has been calculated.

When having loaded a full results (*.dac) file optionally, rate and period budget can be exported to a *.txt file during the calculation by choosing a file name after starting the calculation by hitting the ∫...dt button.

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.