Influence of Porous Medium Geometric Parameters on Superfluid ⁴He Entropy Filter Operation

Superfluid He-4 can be used in cryogenic heat and mass transfer apparatuses efficiently with the aid of an entropy filter based on generation of local hydraulic resistance which only a superfluid phase with almost zero viscosity can overcome. For this, two superfluid phases are separated, followed by use of one of these. Microchinks, chokes, porous media, etc. can act as hydraulic resistance generators. The article analyzes the influence of the geometric parameters of a porous medium (porosity and pore size) on the conditions of superfluid He-4 flow through it. The ranges of steady and transitional conditions of flow of the superfluid component through an entropy filter are determined.