Analysis of the Hydrodynamic Effects in a Surface Textured Circumferential Gas Seal

A theoretical finite-element model was developed to study the hydrodynamic effect of micro-pores generated by laser surface texturing (LST) in a circumferential gas seal. The seal is represented by two non-contacting annular surfaces of a rotating shaft and a stationary ring. The micro-pores of spherical segment shape are distributed uniformly over one of the annular surfaces. The hydrodynamic dimensionless pressure distribution in the uniform clearance between the annular surfaces is obtained from a solution of the Reynolds equation for compressible viscous gas in a laminar flow.

Results of a parametric study along with a numerical example for a specific circumferential seal demonstrate a substantial hydrodynamic effect that can raise the opening average pressure in the seal clearance above the ambient one by up to 50 percent.