Effect of Fin Position on the Dynamic Characteristics of Double Strip Labyrinth Seal

概要

論文の詳細を見る
The fluid force of labyrinth seals may cause unstable rotor vibrations in turbo-machineries. In this research, dynamic characteristics of double strip labyrinth seals were measured by using a test rig. The rotor-bearing system was supported by soft cage springs, and it was excited using a magnetic bearing. Cross-coupled stiffness was calculated and evaluated as unstable dynamic characteristics of the seals. Experimental and calculation results showed cross-coupled stiffness increased, when the rotating speed increased. Otherwise cross-coupled stiffness decreased, when the differential pressure increased. Unstable fluid force of double strip labyrinth seal depends on axial fin position of rotor and stator. When fin position of rotor accord with stator, unstable force arose from upstream cavity and stable force arose from downstream cavity. Upstream of double strip labyrinth seal had a more stabilizing effect, when fin position accord.