Varying clearance, rotor-following seals are a key technology for meeting the demands of increased machine flexibility for conventional power units. These seals follow the rotor through hydrodynamic or hydrostatic mechanisms. Forward-facing step (FFS) and Rayleigh step designs are known to produce positive fluid stiffness. However, there is very limited modeling or experimental data available on the hydrostatic fluid forces generated from either design. A quasi-one-dimensional (1D) method has been developed to describe both designs and validated using test data. Tests have shown that the FFS and the Rayleigh step design are both capable of producing positive film stiffness and there is little difference in hydrostatic force generation between the two designs. This means any additional hydrodynamic features in the Rayleigh step design should have a limited effect on hydrostatic fluid stiffness. The analytical model is capable of modeling both the inertial fluid forces and the viscous fluid losses, and the predictions are in good agreement with the test data.
Investigation of Hydrostatic Fluid Forces in Varying Clearance Turbomachinery Seals
Rugby CV21 2NH, UK
Rugby CV21 2NH, UK
Cranfield MK43 0AL, UK
Durham DH1 3LE, UK
Contributed by the Structures and Dynamics Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received December 8, 2016; final manuscript received August 12, 2017; published online November 21, 2017. Assoc. Editor: Alexandrina Untaroiu.
Tibos, S. M., Georgakis, C., Teixeira, J. A., and Hogg, S. (November 21, 2017). "Investigation of Hydrostatic Fluid Forces in Varying Clearance Turbomachinery Seals." ASME. J. Eng. Gas Turbines Power. May 2018; 140(5): 052502. https://doi.org/10.1115/1.4038136
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