Numerical investigation on transient sealing performance of square labyrinth seal in a liquid hydrogen piston pump

Abstract This paper establishes a two-dimensional transient model of a labyrinth seal that considers the piston’s reciprocating motion to predict transient leakage in a liquid hydrogen piston pump. The sealing performance of a labyrinth seal with square cavities using dynamic mesh techniques to simulate its reciprocating motion is analyzed. The differences between the static and dynamic models, as well as between the labyrinth and clearance seals are numerically compared. The influence of key parameters including piston motion, pressure and geometry on the sealing performance is also examined. As the pressure inside the compression chamber increases, the leakage rate increases. To reduce the leakage rate, it is recommended to increase the number of square cavities and use square cavities with an appropriate length-to-height ratio.