Optimizing the Geometric Parameters of a Stepped Labyrinth Seal to Minimize the Discharge Coefficient
Abstract
:1. Introduction
2. Numerical Method and Verification
3. Results and Discussion
4. Conclusions
- In the stepped labyrinth seal, when CW, SH, and SP were varied, the discharge coefficient of SH was the most sensitive at a factor of approximately 30%;
- In the stepped labyrinth seal, when a small recirculation flow appeared at the clearance inlet, the clearance inlet pressure was reduced, and the axial velocity gently increased, which reduced the size of the vena contracta. The shapes with these characteristics exhibited a small discharge coefficient;
- The wall shear stress and discharge coefficient trends were very similar for the SH changes of the stepped labyrinth seal. However, no correlations existed between the wall shear stress and the discharge coefficient for CW and SP changes.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
Nomenclature
Cross-sectional area of labyrinth seal () | |
AVn | Normalized axial velocity |
Discharge coefficient | |
Normalized clearance | |
CW | Cavity width |
Mass flow rate (kg/s) | |
P | Pressure (Pa) |
R | Specific gas constant |
SH | Step height |
SP | Step position |
T | Temperature (K) |
W | Width of tooth |
Greek Symbols | |
Isentropic coefficient | |
ξ | Coordinate from tooth tip |
Subscripts | |
id | Ideal |
in | Inlet |
out | Outlet |
Superscript | |
* | Normalized |
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Geometry Parameter | Straight-Through Seal [16] | Stepped Seal |
---|---|---|
Number of teeth (N) | 6 | 5 |
Clearance (C) | 0.5 mm | 0.5 mm |
Tooth width (T) | 2.5 mm | 2.5 mm |
Tooth height (H) | 10.5 mm | 10.5 mm |
Cavity width (CW) | 9.5 mm | 3.5–33.5 mm |
Step height (SH) | - | 0–5.6 mm |
Step position (SP) | - | 0.15–10.35 mm |
Surface | Boundary Condition |
---|---|
Inlet | Pressure inlet, 300 K, 202,650 (Pa, absolute pressure) |
Outlet | Pressure outlet, 300 K, 101,325 (Pa, absolute pressure) |
Shaft | 0 RPM, adiabatic wall |
Casing | 0 RPM, adiabatic wall |
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Chun, Y.H.; Ahn, J. Optimizing the Geometric Parameters of a Stepped Labyrinth Seal to Minimize the Discharge Coefficient. Processes 2022, 10, 2019. https://doi.org/10.3390/pr10102019
Chun YH, Ahn J. Optimizing the Geometric Parameters of a Stepped Labyrinth Seal to Minimize the Discharge Coefficient. Processes. 2022; 10(10):2019. https://doi.org/10.3390/pr10102019
Chicago/Turabian StyleChun, Ye Hwan, and Joon Ahn. 2022. "Optimizing the Geometric Parameters of a Stepped Labyrinth Seal to Minimize the Discharge Coefficient" Processes 10, no. 10: 2019. https://doi.org/10.3390/pr10102019
APA StyleChun, Y. H., & Ahn, J. (2022). Optimizing the Geometric Parameters of a Stepped Labyrinth Seal to Minimize the Discharge Coefficient. Processes, 10(10), 2019. https://doi.org/10.3390/pr10102019