Comparative analysis of the influence of labyrinth seal configuration on leakage behavior

This study analyzed the influence of configuration and clearance on the leakage behavior of labyrinth seals. Both computational fluid dynamics (CFD) and an analytical tool were used to predict the leakage flow of two different (straight and stepped) seal configurations with various clearances. The predicted results were compared with experimental data. The CFD gives a better agreement with the experimental result than the analytical model on average. In the straight seal, the dependence of the discharge coefficient on the clearance is considerable, while it is much smaller in the stepped seal. The CFD captures the entire behavior sufficiently well, but the analytical model overpredicts the clearance dependence in the stepped seal. The CFD also predicts well the influence of the flow direction on the leakage flow. The advantage of the stepped seal over the straight seal becomes more evident as the clearance gets larger. As the clearance becomes sufficiently small, the advantage of the stepped seal reduces.