Numerical and experimental study based on reverse jet to suppress leakage flow in the labyrinth seal

Two-dimensional numerical simulations were performed for a straight labyrinth seal passage, nine kinds of sealing structure model were established, the effects of reverse jets at different positions and angles on the internal flow field of the labyrinth were studied emphatically, and the relationship between the front and back pressure ratio of the labyrinth and the leakage coefficient under different models was discussed. The results show that all different jet positions and angles can enhance the seal effect of labyrinth seal, the smaller jet angle, means the better sealing effect, when the jet position was in the middle of the first section of the tooth cavity, the leakage effect was the best. When the jet angle θ was 45 ° and the jet position was in the middle of the first tooth cavity, the leakage coefficient can be reduced by 11.5% corresponding to the case without reverse jets. On the basis of numerical simulation, a two-dimensional straight labyrinth seal experiment with reverse jet was proceeded, using PIV to obtain the flow field with reverser jet under three jet angles and three jet positions, the experimental results were consistent with the calculated variation law.