Different from labyrinth seals,fully-partitioned pocket damper seals can provide greater damping due to the existence of axial baffles,and become potentially effective components to suppress vibration of rotating machinery systems.In order to investigate the influence of structural parameters on the dynamic characteristics of the seal,the force analysis of the through-baffle bag damped sealing-rotor system with small disturbance was carried out.Several groups of cavity depth,sealing gap and basic cavity width were selected to establish the numerical simulation model.CFD method was used to calculate the flow in the seal clearance and the chamber under the given journal vorticity,and the radial force of the journal under the disturbance,as well as the dynamic characteristic coefficients of the system,were obtained.The influences of three structural parameters,namely,chamber depth,seal clearance and basic chamber width,on the dynamic characteristic coefficients of this seal type were analyzed.The results show that the direct stiffness is the dominant factor in the stiffness coefficient,and it increases monotonously with the chamber widening and deepening.The magnitude of direct damping is similar to that of cross damping,and larger chamber depth and smaller seal clearance are beneficial to better damping characteristics.Better sealing dynamic characteristics can be obtained by choosing as deep as possible chamber depth and as small as possible sealing clearance,as well as appropriate sealing width and number of teeth.