结构参数对贯通挡板袋型阻尼密封动力特性的影响

与迷宫密封不同，由于有轴向挡板的存在，贯通挡板袋型阻尼密封能提供较大的阻尼，成为抑制旋转机械系统振动的潜在的有效元件。为探究结构参数对该种密封动特性的影响，对扰动下的贯通挡板袋型阻尼密封-转子系统进行受力分析；选定若干组腔室深度、密封间隙、基本腔室宽度，建立数值仿真模型；利用CFD方法计算给定轴颈涡动下密封间隙和腔室中的流动情况，获得扰动作用下轴颈受到间隙气流的径向作用力，求得密封-转子系统8个动特性系数；分析该型阻尼密封的腔室深度、密封间隙、基本腔室宽度3种结构参数对其动特性系数的影响规律。结果表明：刚度系数中直接刚度为主导因素，且随腔室加宽加深单调增加；直接阻尼和交叉阻尼量级相仿，且较大的腔室深度和较小的密封间隙有利于取得较好的阻尼特性；通过选择尽可能深的腔室深度和尽可能小的密封间隙，以及恰当的密封宽度和齿数，可获得更好的密封动力特性。

Influence of Structural Parameters on Dynamic Characteristics of Fully-Partitioned Pocket Damper Seal

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.