Specific Volume#

Specific Volume = CONSTANT <integer> <float>

Description / Usage#

This card specifies the specific volume of a species. It is required when polymersolvent vapor-liquid phase equilibrium is considered at the material boundaries. Specific volume is used to convert units of mass fraction to volume fraction in species material balance.


Specific volume model type.

  • <integer> - species number

  • <float> - pure component specific volume


Following is a sample card:

Specific Volume = CONSTANT 0 1.154734411

Technical Discussion#

This is the place where pure component density (inverse of specific volume) information is entered in the material property. When Flory-Huggins vapor-liquid equilibrium model was first developed in Goma, the equations were based on volume fractions, not mass fractions. In order to convert these units, the specific volume parameter is required for each component in the mixture.

This card is used only in conjunction with Flory-Huggins nonideal liquid activity model for polymer-solvent mixtures. This occurs when two types of BCs are specified: 1) when VL_POLY is specified at an discontinuous internal boundary and 2) when FLORY model under YFLUX_EQUIL boundary card is specified.


No References.