Annular Gas Seals And Rotordynamics Of Compressors And Turbines.
Abstract
The possible negative or positive impact of annular seal on
rotordynamics of compressors and steam turbines is discussed. The
nature of destabilizing forces that can be developed by "seethrough"
and interlocking labyrinths is discussed. Improving the
rotordynamic behavior of labyrinths via swirl brakes and shunt
injection is explained using measured test results. Improving
rotordynamics through replacement of labyrinths with either
smooth-rotor/honeycomb-stator seals (honeycomb seals) or pocket
damper seals is also discussed. For long seals (L > 2 in or 50 mm)
honeycomb seals leak about a third less than a standard labyrinth,
have much higher values of effective damping, and potentially
high stiffness values for high-pressure compressors. The pocket
damper seal is a patented device with damping values that can be
a hundred times higher than a standard labyrinth seal. Recent test
results are presented for both seal types, and case studies are cited
and reviewed where unstable compressors have been "cured"
through application of these seals.
Description
Tutorialpg. 201-220
Subject
TurbomachinesCollections
Citation
Childs, Dara W.; Vance, John M. (1997). Annular Gas Seals And Rotordynamics Of Compressors And Turbines.. Texas A&M University. Turbomachinery Laboratories. Available electronically from https : / /hdl .handle .net /1969 .1 /163429.