Performance evaluation of trapezoidal teeth labyrinth seal

The present paper investigates the effects of the trapezoidal teeth labyrinth seal on the leakage amount in gas turbines. The influences of increasing the number of teeth from 1 to 6 with step 1 and the tip clearance s=0.5 to 7.5 mm on the leakage flow at different pressure ratios of PR=1.5, 2 and 2.5 are examined, comprehensively. The analysis is performed numerically using a Finite-Volume software with the k-ε turbulent model. The obtained results show a good agreement in comparison with the other research results. The results show that an increase in the number of teeth causes a decrease in the leakage flow. An increase in the tip clearance (s) from 0.5 mm to around 7.5 mm leads to a decrease in the leakage flow, like the step labyrinth behavior, while an increase beyond 7.5 mm results into a leakage increase, the behavior of the straight labyrinth.

Keywords:

Labyrinth , Seal , Trapezoidal , Number of Teeth , Tip Clearance , Leakage Flow , CFD