Porosity = {model_name} <float1> [float2]

Description / Usage#

This card is used to specify the porosity model for the anode or separator or cathode region in a thermal battery cell.

Definitions of the {model_name} and the associated input parameters (<float>) are as follows:


the name of the porosity model.

  • {float1} - the porosity value.


the name of the porosity model.

  • <float1> - the initial value of porosity

  • <float2> - specifies the change of molar volume in the anode or cathode electrode material per electron transferred, as stated in


    where si is stoichiometric coefficient of species or phase i, V is molar volume of species or phase i, n is the number of electrons transfer in the anodic or cathodic electrochemical reaction, and the summation is over the number of solid phases.


A sample input card for this material property might look like this:

Porosity = THERMAL_BATTERY 0.244 8.1185

Technical Discussion#

  • This is a porosity model for a special application in which the model for the diffusion constitutive equation is STEFAN_MAXWELL_CHARGED, which enables modeling the transport of multiple charged species with simultaneous electrochemical reaction(s) in a concentrated solution, as in a thermal-battery cell.

  • See the reference below for a discussion of Thermal Battery modeling with Goma.


SAND2000-0207: Final Report on LDRD Project: A Phenomenological Model for Multicomponent Transport with Simultaneous Electrochemical Reactions in Concentrated Solutions, K. S. Chen, G. H. Evans, R. S. Larson, D. R. Noble and W. G. Houf, January 2000.