intersecting_trapezoids

openpnm.models.geometry.hydraulic_size_factors.intersecting_trapezoids(target, pore_diameter='pore.diameter', throat_diameter='throat.diameter', midpoint=None)[source]

Computes hydraulic size factors for conduits of intersecting trapezoids.

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

  • midpoint (str, optional) – Dictionary key of the midpoint values.

Returns

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

Return type

dict

Notes

The hydraulic size factor is the geometrical part of the pre-factor in Stoke’s flow:

\[Q = \frac{A^2}{8 \pi \mu L} \Delta P = \frac{S_{hydraulic}}{\mu} \Delta P\]

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

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