LAUSR

ABSTRACT The various lengths, clearances, numbers, and rotation angles of swirl brakes are investigated to evaluate their effects on the static and rotordynamic performance of the labyrinth seal using Computational Fluid Dynamics. With increasing number, length and decreasing clearance, the efficiency of the straight swirl brake can be improved. The negative stagger angle could reverse the forward flow. The lean angle has relatively slight effects on the swirl brake. Increasing preswirl ratios tends to increase the circumferential velocity. Compared with the no-brake labyrinth seal, the labyrinth seal with swirl brakes shows lower cross-coupled stiffness and resultant larger effective damping. The effective damping with negative stagger angles is increased about 100% to 200% compared to the straight swirl brakes.