Abstract: To examine commercially high speed (18 000 r/min) dry running non-contacting gas seals, Rotor system of test-bed operated over the critical speed with flexible, squeeze film damper support is designed successfully, including theoretical analysis of characteristics for the ratcage flexible support and the narrow approximation film damper, and transient response for the rigid rotor system. After running during these three years, it has achieved an excellent dynamics property by exper-imental investigatfon. And unsteady phenomena of “bistable” or “lock up” vanish from process of starts or stops.

Key words: Controlling vibration of high speed rotating, Flexible support rotor system, Running test of dry running gas seals, Squeeze film damper