- liquid_mixture_wsd(phase, sigmas='pore.surface_tension.*', rhos='pore.density.*', MWs='param.molecular_weight.*')#
Computes the surface tension of a liqiud mixture with its own vapor using the correlation in 
phase (OpenPNM Phase object) – The phase object to which this model is associated (i.e. attached). This controls the length of the calculated array(s), and also provides access to other necessary properties.
sigmas (str (dict key) or scalar) –
The dictionary key containing the density in kg/m3
MWs : str (dict key) or dict of numeric values for each species
 Winterfeld, Scriven, and Davis