倾斜转子-蜂窝密封系统动力学特性

Dynamic Characteristics of Tilting Rotor-Honeycomb Sealing System

建立了蜂窝密封三维数值模型,采用计算流体力学方法分析了转子倾斜对蜂窝密封泄漏特性和动力稳定性的影响。结果表明:转子倾斜导致蜂窝密封泄漏量减少,倾斜角由0°增加到0.3°,泄漏量降低了1.9%~6.5%;转子倾斜角越大,密封直接刚度系数越大,直接阻尼系数越小;在高频(f>130 Hz)时转子倾斜会导致密封有效阻尼系数减小,易引发轴系稳定性恶化;当转子倾斜时,沿周向同一腔室(2号、7-8号、13号)内的压力均呈正弦规律变化,且随着倾斜角的增大,周向压力绝对幅值增大,同一轴向位置间隙处的压力差增大,密封越易失稳。

A three-dimensional numerical model of honeycomb seal was established,and the influence of a tilting rotor on its leakage characteristics and dynamic characteristics of honeycomb seal was analyzed by computational fluid dynamics method.The results show that tilting rotor can reduce the leakage of honeycomb seal.When the tilting rotor angle increases from 0°to 0.3°,the leakage decreases by 1.9%-6.5%.The larger the tilting rotor angle is,the larger the direct stiffness coefficient is and the smaller the direct damping coefficient is.At high frequency(f>130 Hz),tilting rotor leads to the reduction of effective damping coefficient,which is easy to cause the deterioration of the stability of the rotor-seal system.When rotor tilted,the pressure in the same cavities(No.2,No.7-8,No.13)along the circumference changes in a sinusoidal pattern.With the increase of tilting rotor angle,the absolute amplitude of circumferential pressure increases,the pressure difference at the same axial position gap increases,and the rotor-seal system is more unstable.