Application of Porous Materials to Annular Plain Seals: Part 1—Static Characteristics

Abstract

Porous materials are applied to the annular plain seals employed in pumps by insertion into the inlet part of the seal. The static characteristics of the seals with the porous materials are studied in the laminar-flow regime. The Reynolds equation for the fluid film in the seal clearance is modified to include a so-called filter term, and the pressure equation for the porous matrix is obtained from Darcy’s law and the continuity equation. These equations are applied to the system and are numerically solved with the pressure drop mainly due to the axial acceleration of liquid at the inlet end of the seal being taken into account. Results show that the annular plain seals with the porous materials have larger fluid film force component along the line of centers and smaller one perpendicular to the former than the ordinary solid seals.