spheres_and_cylinders¶
- openpnm.models.geometry.diffusive_size_factors.spheres_and_cylinders(target, pore_diameter='pore.diameter', throat_diameter='throat.diameter')[source]¶
Computes diffusive shape coefficient for conduits assuming pores are spheres and throats are cylinders.
- 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 storedthroat_diameter (str) – Name of the dictionary key on
target
where the array containing pore diameter values is stored
- 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.