Experimental and numerical investigations on the flow characteristics of tower-type labyrinth seal in a compressor stator well

In order to obtain the flow characteristics of labyrinth seal in an aero-engine compressor stator well, experimental and numerical investigations on tower-type teeth with rotating disc cavities at inlet and outlet in the well were carried out. Because of the existence of rotating disc cavities, the development of windage heating and swirl is significant, which has a great influence on the leakage characteristics. The tip clearance is a very important parameter to the labyrinth seal, which was measured by two high-precision laser displacement sensors in real time. The effects of rotational speeds (1500-8100r/min) on the sealing characteristics were studied at different pressure ratios (1.10-1.30). In addition, numerical simulations were carried out according to experimental measurement results. Furthermore, the sealing performance of the tower-type labyrinth seal was compared with that of a straight-through labyrinth seal. The results show that the numerical calculations agree well with the experimental data and the sealing characteristics of tower-type labyrinth seal is better than that of a straight-through labyrinth seal under the experimental conditions. With the increasing of rotational speeds, the working tip clearance, leakage mass flow rate and discharge coefficient decrease. Increasing the rotational speed leads to an increase in the system windage heating. The higher the rotational speed is, the faster the air temperature rises, and the highest dimensionless windage heating reaches around 1.35. Besides, by increasing the rotational speed, the swirl ratio at a specific radial location of the outlet disc cavity increases.