Required Cards:

TRANSPORT_CONDITION <name>

name the condition so that it can be referred to in boundary condition coupler

TYPE <type>

type of the transport boundary condition (options: DIRICHLET, DIRICHLET_ZERO_GRADIENT, NEUMANN, ZERO_GRADIENT, EQUILIBRIUM):

DIRICHLET : Specified concentration

DIRICHLET_ZERO_GRADIENT : Dirichlet (specified concentration) on inflow and zero diffusive gradient on outflow (i.e. only advective transport is considered on outflow).

NEUMANN : Specified solute flux (not currently implemented)

ZERO_GRADIENT : Zero diffusive gradient for inflow and outflow. Not recommended for inflow boundaries.

EQUILIBRIUM : Only applicable to the SOURCE_SINK card. Attempts to set the concentrations at cells within the associated region in equilibrium with the constraint concentrations through a rather hardwired large rate constant. The user should be careful to check that equilibrium is being reached before trusting the code.

CONSTRAINT

Specifies a set of self-consistent solute concentrations.

CONSTRAINT_LIST <a table of time and constraint>

a list of solute concentration constraints that represent changes over time. Step functions are used to interpolate.

Examples

TRANSPORT_CONDITION Initial
  TYPE dirichlet_zero_gradient
  CONSTRAINT_LIST
    0.d0 initial
  /
/

TRANSPORT_CONDITION U_source
  TYPE dirichlet
  CONSTRAINT_LIST
    0.d0 U_source
    336000.d0 Initial
  /
/

: the units for time are seconds by default

CONSTRAINT U_source
  CONCENTRATIONS
    H+       3.0              pH
    Ca++     1.20644e-3       T
    Cu++     1.e-8            T
    Mg++     5.09772e-4       M Dolomite
    UO2++    1E-6             T
    K+       1.54789e-4       T
    Na+      1.03498e-3       Z
    HCO3-    2.57305e-3       T
    Cl-      6.97741e-4       T
    F-       2.09491e-5       T
    HPO4--   1.e-8            M Fluorapatite
    NO3-     4.69979e-4       T
    SO4--    6.37961e-4       T
    Tracer   1.e-7            F
    Tracer2  1.e-7            F
  /
  MINERALS
  :mineral           vol. frac.  area
    Calcite          0.1         1.
    Metatorbernite   0.          1.
  / ! end of minerals
/ ! end of constraint

CONSTRAINT initial
  CONCENTRATIONS
    H+       7.3              M Calcite
    Ca++     1.20644e-3       T
    Cu++     1.e-8            T
    Mg++     5.09772e-4       M Dolomite
    UO2++    2.4830E-11       T
    K+       1.54789e-4       T
    Na+      1.03498e-3       Z
    HCO3-    -3.5             G  CO2(g)
    Cl-      6.97741e-4       T
    F-       2.09491e-5       T
    HPO4--   1.e-8            M Fluorapatite
    NO3-     4.69979e-4       T
    SO4--    6.37961e-4       T
    Tracer   1.e-7            F
    Tracer2  1.e-7            F
  /
  MINERALS
  :mineral          vol. frac.  area
    Calcite         0.1         1.
    Metatorbernite  0.          1.
  / ! end of minerals
/ ! end of constraint