Experimental Study on Static and Dynamic Characteristics of Damper Seals Yieding High Rotor-Stability

为了提高密封的稳定性，对蜂窝孔型阻尼密封进行了静、动特性试验研究。试验使用的密封是三种不同孔深的阻尼器密封（阻尼器密封I: 30mum，阻尼器密封II: 400mum，阻尼器密封III: 500mum深度）和环空平面密封（光滑表面）。所有测试密封件的最小刻度间隙大致相同。结果表明：(1)泄漏流量Q随着密封进出口端压差的增大而增大，而转子旋转速度ω对Q的影响不显著。在相同条件下，阻尼密封的Q值仅为空平面密封的2/3左右，并且随着孔深的增加而减小。(2)减振器密封II的径向反作用力与环空平面密封几乎相同，且大于其他减振器密封。所有减振器密封产生的切向反作用力都比环空密封大。(3)阻尼密封的ω / ω （ω：转子转速）不稳定范围受ω的影响不显著，而环空平密封的ω / ω不稳定范围随ω的增大而增大。这表明，与环空密封相比，进口旋流对密封间隙内圆周流动的影响在质量上对阻尼器密封的影响很小。(4)与环空密封相比，阻尼器密封I的主阻尼系数增加了约70%，阻尼器密封II的主阻尼系数增加了约20%，阻尼器密封III的主阻尼系数增加了约40%。(5)减振器密封比环空平密封具有更好的泄漏性能。从转子稳定性的角度来看，II型阻尼器密封比其他类型的阻尼器密封和环面密封具有更好的动态特性。这表明蜂窝孔型阻尼器密封存在一个合适的孔深。少

In order to improve the seal stability characteristics, the experimental investigation of the static and dynamic characteristics has been developed for the damper seals with honeycombed-holes-pattern. The seals used for the tests are three types of the damper seals with different hole depth (damper seal I : 30mum, damper seal II : 400mum, damper seal III : 500mum in depth) and an annular plain seal (smooth surface). All test seals have approximately the same minimum redial clearance.The results obtainded rea as follows :(1) The leakage flow Q increases with the pressure difference between the inlet and outlet end of the seal, whereas the effect of rotor spinning velocity omega on Q is not significant. Under the same condition, Q for the damper seals is only about 2/3 that of the an nular plain seal, and it decreases with an indrease in the hole depth.(2) The radial reaction fluid-force for the damper seal II is almost the same as that for the annular plain seal, and is larger than thos … More e for the other damper seals. All damper seals yield larger tangenial reaction fluid-force than the annular plain seal.(3) The instability range of OMEGA/omega (OMEGA : rotor whirling velocity) for the damper seals is not significantly affected by omega, while that for the annular plain seal increases with omega. This suggests that the effect of the inlet swirl on the circumferential flow in the seal clearance is qualitatively small for the damper seals as compared to that for the annular plain seal.(4) As compared to the annular seal, an increase in the main damping coefficient has been obtained by approximately 70 percent for the damper seal I,by approximately 20 percent for the damper seal II and by approximately 40 percent for the damper seal III.(5) The damper seals have better leakage performance than the annular plain seal. Furthemore, the damper seal II shows better dynamic characteristics than the other damper seals and the annular plain seals from the viewpoint of yielding higher rotor-stability. This suggests that a suitable hole depth exists for the damper seals with the honeycombed-holes-pattern. Less