Interaction Between Rotor and Annular Seals: Interlaced and Straight-Through Labyrinth Seals

The rotor dynamics and flow characteristics of a seal-rotor system for a straight-through seal and a corresponding interlaced labyrinth seal were computed. The most significant parameters of the rotor dynamic, such as frequency and amplitude of vibration, were determined by numerical methods. These parameters were then used in an unsteady fluid flow simulation. The numerical results indicated that rotor vibration could increase leakage flow and give rise to an additional aerodynamic force that could act on the rotor. Aerodynamic force produced by the straight-through labyrinth seal tended to reduce the self-excited vibration of the rotor, and this effect became more apparent with an increase in pressure difference, which penetrated the seals. The opposite case resulted in the numerical results of the interlaced labyrinth seal. It was found that the vortex and pressure distribution in the seal cavities was the primary cause of these results. Differences between the two types of labyrinth seals were presented in this research.