The efficiency of a non-contact seal tends towards its maximum value if its outflow rate tends towards zero. In these conditions, the hypothesis that the evacuation of heat resulted inside the axial clearance is made predominantly through the seal body/walls has been experimentally demonstrated as just. If the considerations adopted aren’t modified, one can reach the conclusion that for non-contact seals the heat evacuation is made only through its body. The methodology and analytical relations needed in the study of the thermal transparency for an axial-cylindrical non-contact seal constitutes the object of the present paper.
