Numerical investigation on leakage and rotordynamic performance of the honeycomb seal with swirl-reverse rings

Honeycomb seals are a crucial component to restrict the leakage flow and improve system stability for the turbomachines and aero-engines. In this work, the leakage and rotordynamic performance of honeycomb seals with the Swirl-Reverse Ring (SRR) is predicted by employing the approach of Computational Fluid Dynamics (CFD) and the multifrequency whirling model theory. Numerical results show that the positive preswirl flow and circumferential velocity can be effectively weakened for the honeycomb seal as SRR is introduced. The obtained results also suggest that the direct stiffness, direct damping, and effective stiffness will not reduce, for the honeycomb seal is introduced to SRR. However, the honeycomb seal with SRR can significantly reduce the cross-coupled stiffness and remarkably enhance the effective damping. Meanwhile, the absolute value of negative tangential force acting on the rotor surface significantly increased for the honeycomb seal introduced SRR. Therefore, the whirling velocity of the rotor would be weakened. This phenomenon would be conducive to improve the stability of the rotor. Besides, the performance of SRR can be further enhanced when SRR possesses a smaller bending angle, and a higher arrangement density and height.