Analysis of rotordynamic forces for high inlet pre-swirl rate labyrinth seals

摘要

Labyrinth seals are widely used in various kinds of turbo machines and they can change rotordynamic properties of the system by generating forces on the rotor. A linearized model has been widely used by previous researchers to describe the rotordynamic properties of the labyrinth seal. However, recent predictions of the rotordynamic coefficients using a CFD analysis approach have shown that the linearized first-order model could not accurately describe the characteristics for high pre-swirl cases; therefore a second-order model including inertia terms was built and applied for rotordynamic analysis. The results confirmed the necessity of the second-order model in high pre-swirl conditions.