Abstract
Measurements of temperature distribution inside porous-plugs were carried out to understand actual flow phenomena inside plugs. It is found that He II flows ideally, i.e. the London equation is valid, through the most part of a plug. The flow of the normal component remains laminar under any experimental conditions. He II flow finally changes to vapor one in the downstream most part of a plug. Large drops in temperature and pressure across a plug are caused in the vapor flow region. A thermodynamic consideration of porous-plug phase separation is also presented.
