NairnFEAMPM Icon

Concentration Command

The Concentration command sets concentration potential or transport value conditions to all nodes selected by the GridBC command that encloses it:

 Concentration (style),(value),<(time)>,<(phaseStyle)>

where (style) specifies the style of the applied concentration potential or transport value. Each condition depends on two parameters specified by arguments (value) and (time). If either argument is not supplied, they are set to zero. The standard units are dimensionless concentration potential or transport value for (value) and alt time units for (time) (but the units may change depending on the (style) setting).

By default, Concentration command set solvent concentration potential on a node. The (phaseStyle) command can set boundary conditions instead for other transport tasks. The options are:

  1. "solvent" (or 1) - solvent diffusion (the default)
  2. "fracture" (or 3) - fracture phase field value (0 to 1)
  3. "battery" (or 4) - battery phase field value (0 to 1)
  4. "conduction" (or 5) - battery conduction equation value (in volts)

Note that "pressure" (or 2) corresponds to a pore pressure boundary condition, but that should be set instead with a PorePressure command.

Notes

  1. The Concentration command can only be in GridBC blocks which are only allowed for MPM analyses.