Investigation of performance and parametric optimization of the typical spiral groove dry gas seal under transient disturbance operating condition

Due to the great vibration of the rotating shaft, the dry gas seal has a transient change in film thickness during operation, which seriously affects the performance and lifetime of the dry gas seal. The current research on dry gas seals has begun to focus on their dynamic behavior. However, detailed analysis of the transient performance of dry gas seals under transient disturbance operating conditions is lacking. In this paper, the transient performance of spiral groove, upstream pumping spiral groove and double-row spiral groove DGS are studied under axial displacement disturbances. The dynamic model of a gas film sealing system is established, which is solved simultaneously with transient Reynolds question by direct numerical simulation method. The maximum amplitude and decay time are selected to investigate the effect of structural and mechanical characteristics parameters on the transient performance. The results show that the upstream pumping spiral groove can restore the stable operation in the shortest time under axial displacement disturbance, but its leakage rate increases significantly compared to the steady state. However, when the sealing pressure increases, the stability advantage of the upstream pumping spiral groove is significantly reduced, and the sealing system can only recover the equilibrium film thickness after a long period of small vibrations. Spiral groove and double-row spiral groove dry gas seal are more sensitive to displacement disturbances, which aggravates the possibility of wear and collision of sealing rings.