Low Leakage Designs for Rotor Teeth and Honeycomb Lands in Labyrinth Seals

Design improvements on labyrinth seal teeth and a honeycomb land are examined by three-dimensional CFD numerical modeling of the flow field. The only objective is reduction of the total leakage through the new seal. CFD assumptions and analysis was validated by comparison with leakage data from labyrinth seal experiments conducted by Stocker [1]. The baseline chosen for comparison of sealing effectiveness is a conventional low clearance straight-through labyrinth seal with four teeth and a honeycomb land of symmetrical hexagonal cells. The proposed new seal has a staggered honeycomb land and straight teeth with an inclined notch. CFD predicts ∼17% reduction in seal leakage at a radial clearance of 0.005 inch (0.122mm) due to higher wall friction and flow turbulence.