近年来,一类在传统迷宫密封梳齿间增添蜂窝的复合密封结构逐步应用于叶片式压缩机等高速透平机械.为探究梳齿角对复合密封的泄漏及动力特性的影响,结合某叶片式压缩机优化设计实际需求,建立了静子齿复合密封(TOS CS)、转子齿复合密封(TOR CS)两种复合密封的三维模型,采用数值模拟方法分析在半频涡动下梳齿角对两种复合密封的泄漏及动力特性的影响.结果表明:TOR CS的泄漏量随着梳齿角的增大而减小,而TOS CS存在一个临界角度θcr,梳齿角低于θcr时,泄漏量随着梳齿角的增大而减小,梳齿角高于θcr时,泄漏量随着梳齿角的增大而增大.两种复合密封的泄漏量随压缩机的压比的增大而升高,压比的增大对小梳齿角TOS CS、大梳齿角TOR CS泄漏量影响较大.在半频涡动下,相同梳齿角的TOS CS有效阻尼比TOR CS高56.4%～61.2%,随着梳齿角的增大,TOS CS与 TOR CS 直接刚度、交叉刚度降低,直接阻尼增大,TOS CS 与 TOR CS 的有效阻尼分别提升了89.5%、83.2%,转子稳定性可得到提升.研究结论为高转速透平机械的复合密封结构优化设计提供了有力支撑.
The Influence of Comb Angle on Leakage and Dynamic Characteristics of Compound Seal Combined Labyrinth with Honeycomb
In recent years,a kind of compound seal structure combined honeycomb with the traditional labyrinth seal had been gradually applied to vane compressor and other high-speed turbine machinery.In order to investigate the influence of comb Angle on the leakage and dynamic characteristics of compound seals,combined with the actual requirements of optimization design of a vane compressor,three-dimensional models of stator tooth compound seals(TOS CS)and rotor tooth compound seals(TOR CS)were established.The effects of comb Angle on the leakage and dynamic characteristics of two kinds of compound seals under half-frequency vortex were analyzed by numerical simulation.The results show that the leakage of TOR CS decreases with the increase of tooth Angle,while that of TOSCS has a critical Angle θcr,when the tooth Angle is lower than θcr,the leakage decreases with the increase of the tooth Angle,and when the tooth Angle is higher than θcr,the leakage increases with the increase of the tooth Angle.The leakage of the two composite seals increases with the increase of the compressor pressure ratio,and the increase of the pressure ratio has a great influence on the leakage of small comb Angle TOS CS and large comb Angle TOR CS.Under half-frequency vortex,the effective damping of TOSCS with the same comb Angle is56.4%～61.2%higher than that of TOR CS.With the increase of comb Angle,the direct stiffness and cross stiffness of TOS CS and TOR CS decrease,while the direct damping increases,and the effective damping of TOS CS and TOR CS increases by 89.5%and 83.2%,respectively.Rotor stability can be improved.The research results provide a strong support for the optimal design of compound seal structure of high-speed turbine machinery.
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