Numerical Investigation of Flow Through Labyrinth Seals in Gas Turbine Engines

Labyrinth seal is frequently used in turbomachines and mostly preferred in blade tip regions. They can operate under high-temperature and high-pressure rates and provide successful sealing for high-speed rotating parts. Other advantages include ease of manufacture, inexpensive supply etc. Within the scope of this paper, different seal geometries with various clearances and inlet conditions are examined by using CFD analysis to illustrate their effects on the sealing performance. CFD analyses are carried out by using a compressible turbulent flow model in two dimensional coordinates using FLUENT software. The analyses are verified by comparing experimental results that are published in the literature of some similar applications. In addition, the leakage flow rate obtained from CFD analyses are compared with the well-known labyrinth seal correlations and experimental results. In labyrinth seals, the fluid total temperature will change as a result of work transfer from the rotor surfaces. Windage computations are performed as a result of the rotor power input into the surrounding fluid. As a result of windage, the total temperature of fluid increased. Windage for different geometries and entrance conditions are examined for minimum cooling air temperature.