Analysis on Dynamic Tracking Characteristics of Dry Gas Seals During Start-up Process

Based on the small perturbation method, the transient pressure control equation considering real gas effects was solved, and the fitting expression for the dynamic characteristic parameters of the gas film during the start-up process was obtained. Subsequently, the influence of structural parameters of spiral groove dry gas seals on the dynamic tracking of the stationary ring's motion during the non-steady-state start-up process under three degree of freedom perturbations was analyzed. The results show that when the stationary and rotating rings initially separate, the stationary ring exhibits good tracking performance for both axial and angular motions of the rotating ring, although the tracking capability varies significantly. As time and film thickness increase, the tracking capability gradually weakens, and at the working film thickness, the tracking parameters tend to stabilize when the working film thickness is reached. Larger spiral angles and deeper dynamic pressure grooves, the poorer the axial and angular tracking performance of the sealing ring. The number of grooves has a minimal impact on the axial and angular tracking performance of the stationary ring. A higher balance coefficient improves the axial and angular tracking performance of the stationary ring.