Cell Pathway Outputs

Cell pathways have at least one output:

• Mass_in_Pathway. This is a vector A one-dimensional array. by species The chemical (or non-chemical, such as bacterial or viral) constituents that are stored and transported through an environmental system in a contaminant transport model. In GoldSim, the Species element defines all of the contaminant species being simulated (and their properties). with dimensions An output attribute for an element that defines the dimensionality (in terms of Length, Time and other fundamental dimensions) of the output. of mass. It represents the total mass of each species in the Cell.

Note: The Mass_in_Pathway output is the primary output For an element with multiple outputs, the output that has the same name as the element. for the Cell. Hence, if you right click on a Cell in Result Mode The state of a model when it has been run and contains simulation results for a single set of input parameters. and select a result to display, it will display the Mass_in_Pathway output.

In addition, if the Output Precipitated Mass checkbox is selected at the bottom of the Cell dialog, an additional output is added to the Cell:

• Precipitated_Mass. This is a vector by species with dimensions of mass. It represents the total amount of mass of each species in the Cell that is currently precipitated.

Note: Precipitated_Mass can be non-zero even in the absence of solubility limits. If none of the Fluids in the Cell have non-zero volumes, then any mass in the Cell will precipitate out onto any Solids present in the Cell (proportional to the mass of each Solid) even if no solubility limit is specified.

For every medium that you add to the Cell, an output is created on the Cell:

• Concentration_in_Medium, where Medium is the name of the medium you have added. This is a vector by species. If the medium is a fluid, it has dimensions of mass per volume. If the medium is a solid, it has dimensions of mass per mass.

If one or more Solids are suspended in a Fluid, the fluid concentration is computed as the effective concentration, which includes the suspended solids:

where:

c_i = the effective concentration in the fluid (M/L³);
cd_i = the dissolved concentration in the fluid (M/L³);
m_part,k = the mass of particulate solid k in the cell (M);
V = the volume of the fluid in cell (L³);
csorb_k,i = the concentration of species i in particulate solid k (M/M); and
NK = the number of solids suspended in the fluid.

If the Cell contains a suspended Solid, then an additional output is added:

• Dissolved_Conc_in_Fluid, where Fluid is the name of the fluid directly above the suspended Solid in the list or media Materials (such as water, sand, clay, air) that constitute (are contained within) transport pathways. GoldSim provides two types of elements for defining media: Fluids and Solids.. It represents the dissolved concentration of species in the fluid (excluding the contribution from suspended solids). This is a vector by species. It has dimensions of mass per volume.

Finally, GoldSim also creates a Cell output for each mass flux link An interconnnection between two transport pathways that defines the rate at which species move between the pathways. created from the Cell to other pathways. Two types of mass flux links can be created from a Cell: advective links and diffusive links.

For every advective mass flux link A mass flux link in which a quantity of a medium is specified to flow from one pathway to another, carrying dissolved, sorbed, and/or suspended species with it. in which the Cell is the Outflow (upstream) pathway, an output is created on the Cell:

• Medium_to_Path2, where Medium is the name of the flowing medium, and Path2 is the name of the linked (Inflow) pathway. This is a vector by species, and has dimensions of mass/time. It represents the mass flux of each species from the Cell to the downstream pathway.

For every diffusive mass flux link A mass flux link in which species diffuse between pathways according to a concentration gradient. in which the Cell is the Outflux pathway, an output is created on the Cell:

• Medium1_to_Medium2_in_Path2, where Medium1 is the name of the fluid on the Outflux side of the link, Medium2 is the name of the fluid on the Influx side of the link, and Path2 is the name of the linked (Influx) pathway.

For every direct transfer mass flux link in which the Cell is the Outflow (upstream) pathway, an output is created on the Cell:

• Direct_transfer_rate_to_Path2, where Path2 is the name of the linked (Inflow) pathway. This is a vector by species, and has dimensions of mass/time. It represents the mass flux of each species from the Cell to the downstream pathway.

For every precipitate removal mass flux link in which the Cell is the Outflow (upstream) pathway, an output is created on the Cell:

• Precipitate_transfer_rate_to_Path2, where Path2 is the name of the linked (Inflow) pathway. This is a vector by species, and has dimensions of mass/time. It represents the mass flux of each species from the Cell to the downstream pathway.

For every treatment mass flux link A mass flux link in which species are filtered (treated) as they are moved from one pathway to another based on a user-specified fraction (treatment efficiency). in which the Cell is the Outflow (upstream) pathway, an output is created on the Cell:

• Fraction_of_inflows_to_Path2, where Path2 is the name of the linked (Inflow) pathway. This is a vector by species, and has dimensions of mass/time. It represents the mass flux of each species from the Cell to the downstream pathway.

It is important to understand that the mass flux outputs from a Cell represent the mass rate over the previous timestep A discrete interval of time used in dynamic simulations.. This can have implications if you choose to integrate one of these outputs (using an Integrator).