Viscosity -- capillary radius, and permeability threshold

[fargoth]

In a demonstration of the qualities of liquid Helium in type 1, and type 2 the fact that a super-fluid can permeate through capillaries which are too small for type 1 Helium to pass through.

I was wondering about the equation which determines the capillary radius threshold under which the porous barrier is no longer permeable. Doesn't it also depend on the surface tension?

 

[Illmatic1]

The equation which determines the capillary radius threshold at which a porous barrier is no longer permeable is called the Young-Laplace equation. It states that the pressure difference between two points across the barrier is equal to the surface tension multiplied by the curvature of the surface. This equation can be used to calculate the maximum capillary radius for a given surface tension and pressure difference. In the case of liquid Helium, the surface tension of type 1 and type 2 are different, so the maximum capillary radius for each type will also be different.