Research on the operation mechanism and performance of bump-type compliant foil face gas seal

This paper presents a bump-type compliant foil face gas seal (BCFFGS), a novel face gas seal. A theoretical model of BCFFGS, which couples the Reynolds equation and foil deformation equation, is proposed and solved by the finite difference method. In addition, comparative analyses of the action law between BCFFGS and rigid surface face gas seal (RSFGS) are made in terms of film pressure, film thickness, and flow field to investigate the operation mechanism of BCFFGS. A range of preferred values for structural parameters is obtained by studying the influence of structural parameters on sealing performance parameters of BCFFGS. Numerical results indicate the intrinsic relationships among film pressure, foil deformation, and film thickness for BCFFGS. Furthermore, from the performance analysis of BCFFGS and RSFGS under different linear velocities and media pressure, it can be seen that BCFFGS has more outstanding comprehensive performance compared with RSFGS under the scope of the parameters studied in this paper. Regarding BCFFGS, it has the best sealing performance, as well as stability, at the slope ratio of 0.2–0.3, the foil-dam ratio of 1.5–1.8, and the number of cycles of 12–16.