compactness

openpnm.models.geometry.throat_capillary_shape_factor.compactness(target, throat_perimeter='throat.perimeter', throat_area='throat.area')

Mortensen et al. have shown that the Hagen-Poiseuille hydraluic resistance is linearly dependent on the compactness. Defined as perimeter^2/area. The dependence is not universal as shapes with sharp corners provide more resistance than those that are more elliptical. Count the number of vertices and apply the right correction.

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.

• throat_perimeter (string) – The dictionary key of the array containing the throat perimeter values

• throat_area (string) – The dictionary key of the array containing the throat area values

Returns

alpha – Array containing throat compactness values.

Return type

NumPy ndarray

References

Mortensen N.A, Okkels F., and Bruus H. Reexamination of Hagen-Poiseuille flow: Shape dependence of the hydraulic resistance in microchannels. Physical Review E, v.71, pp.057301 (2005).