squares_and_rectangles

openpnm.models.geometry.diffusive_size_factors.squares_and_rectangles(target, pore_diameter='pore.diameter', throat_diameter='throat.diameter', pore_aspect=[1, 1], throat_aspect=[1, 1])[source]

Computes diffusive size factor for conduits assuming pores are squares and throats are rectangles.

Parameters

  • target (OpenPNM Base object) – Object with which this model is associated. This controls the length of the calculated array, and also provides access to other necessary properties.

  • pore_diameter (str) – Name of the dictionary key on target where the array containing pore diameter values is stored

  • throat_diameter (str) – Name of the dictionary key on target where the array containing pore diameter values is stored

  • pore_aspect (list) – Aspect ratio of the pores

  • throat_aspect (list) – Aspect ratio of the throats

Returns

size_factors – A dictionary containing the diffusive size factors, which can be accessed via the dict keys ‘pore1’, ‘pore2’, and ‘throat’.

Return type

dict

Notes

The diffusive size factor is the geometrical part of the pre-factor in Fick’s law:

\[n_A = \frac{A}{L} \Delta C_A = S_{diffusive} D_{AB} \Delta C_A\]

Thus \(S_{diffusive}\) represents the combined effect of the area and length of the conduit, which consists of a throat and 1/2 of the pore on each end.

This model should only be used for true 2D networks, i.e. with planar symmetry.