Pressure Drop of He II Flow Through a Porous Media

Abstract

The behavior of liquid helium in porous materials continues to be of interest for the purpose of helium fluid management in a weightless environment. The present paper reports on measurements of He II pressure drop across two porous SiO₂ ceramic filter materials. These materials vary only in porosity, having values of 0.94 and 0.96. The average fiber diameter in both cases is approximately 5 µm. The experiment consists of a glass tube containing a piece of this sponge in one end. The tube is rapidly displaced downward in a bath of helium and the liquid levels allowed to equilibrate over time producing variable velocities up to 10 cm/s. The results are compared with those previously obtained using fine mesh screens. Good qualitative agreement is observed for turbulent flow; however, the behavior in the laminar flow regime is not fully understood.