Measurement and Prediction of Rotordynamic Forces for Labyrinth Seals

摘要

Measurements of rotordynamic (stiffness and damping) coefficients and leakage characteristics were completed for labyrinth-rotor/honeycombe-stator seals. Comparisons to labryinth-rotor/smooth-stator seals showed no stability improvements. Tests were also carried out on smooth-rotor/honeycombe-stator seals and demonstrated superior stability and leakage performance for this type of seal if the entering flow is pre-rotated in the direction of rotation. A new 'bulk-flow' theory for labyrinth seals has been developed and its predictions compare well with measured results for tooth-on-rotor labyrinths. Also, a more sophisticated model was developed which solves the 3-D Reynolds-averaged Navier-Stokes equations for compressible flow. Keywords: Labyrinth seals, Rotordynamic forces, Turbine stators, Computational fluid dynamics. (jes)