阶梯式迷宫密封泄漏量和动特性数值研究

涡动转子与迷宫密封中的泄漏流体相互作用能产生诱发涡轮机械失稳的气流激振力。迷宫密封动特性系数能描述激振力的重要特性。传统的迷宫密封动特性分析方法基于整体流动理论,尽管求解迅速,但对工作在小间隙、高速、高压条件下的密封动特性预测精度不高,且不适用于求解复杂结构密封的动特性。为了提高迷宫密封动特性的预测精度,利用三维计算流体动力学方法模拟迷宫密封内部流动。这一方法适合于任意齿形和结构的迷宫密封,当仅计算泄漏量时采用轴对称模型,计算激振力采用三维偏心模型。计算结果与实验数据比较,表明计算流体动力学方法预测阶梯迷宫密封的泄漏量和动特性系数精度较高。

Numerical study of leakage and dynamic coefficients of stepped labyrinth gas seals

Rotor- fluid interactions can cause self- excited vibrations in turbomachines.The labyrinth seal forces are characterized by rotordynamic coefficients.Traditional labyrinth seal models are based on bulk - flow assumptions. These models,while efficient to compute,typically show poor prediction for seals with small clearances,high running speed,and high pressure.In an effort to improve the prediction of these components this work utilizes three-dimensional computational fluid dynamics(CFD) to model the labyrinth seal flow path.The method allows modeling of any arbitrarily shaped domain labyrinth seal.When only leakage prediction is required,an axisymmetric model is created. To calculate rotordynamic forces,a full 3D,eccentric model is solved.The results demonstrate improved leakage and rotordynamic prediction over bulk - flow approaches compared to experimental measurements.