HydroGeoSphere/Solute Mass Balance
Sample solute mass balance output
editBy default, solute mass balance information for each species is computed at each time step and written to the prefixo.lst file. Figure 5.18 shows some sample output as it appears in the .lst file:
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MASS BALANCE SPECIES 1 - Uranium
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(Time = 1999.00999999978 Time-step = 9.999999776482582E-003 )
RATE OF MASS EXCHANGE IN OUT
TOTAL
Fixed head nodes 100.0000006818 0.0000000000
Fixed concentration nodes 150.0985515732 0.0000000000
NET1 EXCHANGE RATE (IN-OUT) 250.0985522550
MASS ACCUMULATION COMPONENT SUBTOTAL
In storage:
Porous medium 2.5001748233
Porous medium (sorbed) 35749.9997988755
ACCUMULATED 35752.4999736989
Lost by decay:
Porous medium 0.0000000708
Porous medium (sorbed) 0.0010116896
DECAYED 0.0010117604
EXCHANGED (via chemical reactions) 0.0000000000
INITIAL (stored at start of timestep) 35750.0000000000
NET2 RATE OF ACCUMULATION 250.0985515100
i.e. (ACCUMULATED -DECAYED +(-)EXCHANGED -INITIAL)/delta
NET (since start of simulation) 250.0985515100
MASS BALANCE ERROR
Absolute: (NET1-NET2) 0.0000007450
Relative: (NET1-NET2)/(abs(NET1)+abs(NET2))/2.0 0.0000000015
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- Figure 5.18: Sample Mass Balance Information for Example PM CD
No solute mass balance
editThis instruction prevents solute mass balance information from being written to the listing file.
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This detailed mass balance information is also written to a TECPLOT formatted ascii output file called, for example, prefixo.mass_balance_species_001 so that it can be easily visualized.
Summary mass balance information
editSummary mass balance information is written to a TECPLOT formatted ascii output file called, for example, prefixo.mass_balance_summary so that it can be easily visualized. For each timestep in the transport solution, one line per species is written to the file. Each line has columns labelled as follows:
- time Simulation time.
- Tmass Total mass in the system.
- dBoundary Change in mass due to sources and sinks.
- dStored Change in mass stored.
- dBoundary - dStored Error.
- (dBoundary - dStored)/Tmass*100) Normalized error.
- Species Species number.
Besides being plotted with TECPLOT, such output can be imported into an editor (e.g. Microsoft Excel) and sorted to facilitate, for example, the creation of a plot of mass balance error versus time for a given species.
Cumulative mass balance information
editCumulative mass balance information is written to a TECPLOT formatted ascii output file called, for example, prefixo.mass_balance_cumulative so that it can be easily visualized. For each timestep in the transport solution, one line per species is written to the file. Each line has columns labelled as follows:
- time Simulation time.
- In (cumulative) Mass in since start of simulation.
- Out (cumulative) Mass out since start of simulation.
- Stored Change in mass stored since start of simulation.
- In+Out-Stored Error.
- Species Species number.
Besides being plotted with TECPLOT, such output can be imported into an editor (e.g. Microsoft Excel) and sorted to facilitate, for example, the creation of a plot of mass balance error versus time for a given species.