Prediction of Carry- over Coefficient for Fluid Flow through Teeth on Rotor Labyrinth Seals Using Computational Fluid Dynamics

Abstract

The analysis presented in this work deals with the computational fluid dynamics (CFD) based modeling for the carry-over coefficient of flow through teeth on rotor straight through labyrinth seal. A two dimensional model for the flow through the seal was built in FLUENT 6.3.26. A grid independence study was carried out showing the influence of grid refinement on the fluid mass flow rate. The effect of turbulence modeling, seal geometry and shaft rotational speed have been taken into consideration. Three CFD models to predict the carry-over coefficient considering the effect of the parameters mentioned before have been presented. The prediction models have been validated against experimental works conducted by  Scharrer (1988) and Eser (2004).  The results obtained in the present work for the effect of different parameters, namely, (Number of teeth, Reynolds number, rotational speed and seal geometry) for two labyrinth seals with (0.127mm) and (0.33mm) tooth clearance have been presented. A prediction equation for the carry-over coefficient of the labyrinth seal has been proposed through this work. Verification for some of the results obtained through this work with that published by other workers has been carried out. The results obtained through the present work found to be in a good agreement with the results of other workers.

Key words: Labyrinth seal, Carry-over coefficient, CFD.