• Title/Summary/Keyword: staggered labyrinth gas seal

Search Result 2, Processing Time 0.02 seconds

Leakage and Rotordynamic Analysis for Staggered-Labyrinth Gas Seal (엇갈린 래버린스 실의 누설량 및 동특성 해석)

  • Ha, Tae-Woong
    • Tribology and Lubricants
    • /
    • v.18 no.1
    • /
    • pp.24-33
    • /
    • 2002
  • The basic equations are derived for the analysis of a staggered labyrinth gas seal which are generally used in high performance compressors and steam turbines. The Bulk-flow is assumed for a single cavity control volume and the flow is assumed to be completely turbulent in circumferential direction. Moody's wall-friction-factor formula is used for the calculation of wall shear stresses in the single cavity control volume. For the reaction force developed by the seal, linearized zeroth-order and first-order perturbation equations are developed for small motion about a centered position. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the staggered labyrinth gas seal. Theoretical results of leakage and rotordynamic characteristics for the staggered labyrinth gas seal are compared with those of the plain seal and see-through labyrinth seal.

Prediction of Combination-Type-Staggered-Labyrinth Seal Leakage Using CFD (CFD를 사용한 복잡한 형상을 갖는 래버린스 실의 누설량 예측)

  • Ha Tae-Woong
    • Tribology and Lubricants
    • /
    • v.22 no.2
    • /
    • pp.66-72
    • /
    • 2006
  • Leakage reduction through annular type labyrinth seals of steam turbine is necessary for enhancing their efficiency and the precise prediction method of seal leakage is needed. In this study, numerical analysis for leakage prediction of the combination-type-staggered-labyrinth seal has been carried out using FLUENT 6 which is commercial CFD (Computational Fluid Dynamics) code based on FVM (Finite Volume Method) and SIMPLE algorism. The present CFD results are verified with the theoretical analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage. Comparing with the result of Bulk-flow model analysis, the leakage result of CFD analysis shows good agreement within 7.1% error.