On the dynamic performance of a novel airfoil guider seal with the controlled circumferential flow: Numerical analysis and experimental validation

The positive circumferential flow is the major cause of seal instability. This paper proposes the airfoil guider seal (AGS) with specially designed airfoil guiders in cavities. The pressure difference between the suction and pressure surfaces induced by the airfoil guiders controls the circumferential flow. To validate the novel design, the flow field and flow-induced tangential force of the AGS are numerically calculated and compared with these of labyrinth seals (with/without swirl brakes), and pocket damper seal. The aerodynamic work and rotordynamic coefficients of the AGS are experimentally identified and compared with these of the labyrinth seal (with/ without swirl brakes). With the airfoil guiders, the positive circumferential flow is effectively controlled. The AGS possesses the best stability among the studied seals.