Abstract
The following paper presents dynamic leakage rate and coupled interaction for variable speed rotor-labyrinth (LABY) seal, with rotating speed from 18 to 30 krpm. Variable speed rotor vibration characteristics are incorporated into transient computational fluid dynamic (CFD) calculations as boundary conditions of seal flow field to show the real-time effect of rotordynamic in seal flow field. Leakage rate across a variable speed rotor-seal increases with rotor vibration, but this effect is prominent at lower speed than at higher speed. Leakage characteristic is determined by differences in rotor vibration amplitude rather than rotating speed. The results also reveal that aerodynamic forces of labyrinth seal flow field can improve rotor stability, and this interaction between rotor and seal decreases with the increase of rotating speed.
Funding statement: Postdoctoral Science Foundation of China (Grant/Award Number: 2015M571393).
Acknowledgment
The authors wish to thank the financial support of Postdoctoral Science Foundation of China (2015M571393).
Nomenclature
Vibration amplitude of rotor (mm)
Vibration frequency of rotor (Hz)
Aerodynamic force on the rotor (N)
Time in vibration (s)
Mass flow (kg/s)
Rotating speed of rotor (r/min)
Pressure difference (Mpa)
Thickness of throttled tooth (mm)
Initial height of radial clearance (mm)
Dynamic height of radial clearance(mm)
Flow coefficient
Outlet static pressure (Mpa)
Averaged flow coefficient
Inlet total pressure (Mpa)
Inlet total temperature (°C)
Number of sealing teeth
Leakage area of seal (m2)
Leakage with no vibration (kg/s)
Dynamic leakage (kg/s)
Height of the first layer mesh (m)
Velocity of motion of the first layer mesh (m/s)
- Subscripts
Radial direction
Tangential direction
References
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