Abstract
The objective of this work is to observe the effects of friction factors for the stepped labyrinth seals. The gas flow through the seals creates net pressure and shear forces acting on the rotor. It is necessary to predict these forces for reliably operating turbomachinery. So we investigated the effect of shear forces on the calculation of rotordynamic coefficients by comparing the results in the case shear forces are considered and in the case they are neglected. We also compared our results, obtained with the Colebrook–White friction factor model, with some reference experimental and computational results.
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Abbreviations
- A i :
-
Circumferential clearance area of seal
- a r :
-
Dimensionless rotor shear area
- a s :
-
Dimensionless stator shear area
- B :
-
Height of seal stript
- C :
-
Direct damping coefficients
- c :
-
Cross damping coefficients
- C r :
-
Radial clearance
- d :
-
Step height
- D h :
-
Hydraulic diameter of cavity
- f :
-
Friction factor
- K :
-
Direct stiffness coefficients
- k :
-
Cross coupled stiffness coefficients
- L :
-
Pitch of seal strips
- ṁ:
-
Leakage mass flow
- m,n :
-
Coefficients for friction factor
- NT:
-
Number of the teeth
- P :
-
Pressure
- q :
-
Tooth tip width
- R :
-
Gas constant
- Re :
-
Reynolds number
- R s :
-
Seal radius
- R sw :
-
Surface velocity of rotor
- T :
-
Temperature
- U :
-
Flow velocity to the wall
- V :
-
Circumferential velocity
- w :
-
Shaft angular velocity
- γ:
-
Ratio of spesific heats
- μ 1i :
-
Contraction coefficient
- μ 2i :
-
Kinetic energy carry-over coefficient
- ρ i :
-
Density
- τ si :
-
The shear stress of the stator surface
- τ ri :
-
The shear stress of the rotor surface
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Eser, D., Dereli, Y. Comparisons of rotordynamic coefficients in stepped labyrinth seals by using Colebrook-White friction factor model. Meccanica 42, 177–186 (2007). https://doi.org/10.1007/s11012-006-9036-4
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DOI: https://doi.org/10.1007/s11012-006-9036-4