迷宫通道内部流动和泄漏特性的数值分析

NUMERICAL ANALYSIS OF FLOW AND LEAKAGE IN LABYRINTH SEAL

求解非定常Ｎ－Ｓ方程，数值预测了深宽比Ｈ／Ｗ分别为０．１、０．３和０．５的单空腔直齿迷宫通道的内部流动，计算结果展示了流动结构的振荡及出口泄漏量下降和回升的波动。３种结构的密封效果优劣与泄漏量波动幅度大小相对应，其排列顺序是深宽比Ｈ／Ｗ分别为０．３、０．５和０．１的结构。还讨论了涡运动与涡合并、分离泡的迁移、射流的弯曲及对空腔壁面的冲击等复杂物理过程的内在联系，分析了射流冲击所产生的多种效应对增加能耗减小泄漏的作用。

The unsteady Navier stokes equations are solved to predict numerically the internal flow of single cavity labyrinth channel with depth to width ratios H/W=0 1,0 3 and 0 5.The numerical results demonstrate the oscillation of the flow structure and fluctuation of the exit leakage rate.It is shown that the seal efficiency is relevant to the amplitude of leakage fluctuation,furthermore,the sequence of H/W from 0 3,0 5 to 0 1 is also the order of both increasing seal efficiency and increasing amplitude of leakage fluctuation.Also,the complex physics,including motion and mergences of vortex,migration of separation bubble,bending and impact of jet,is discussed,and the influence of impact effects on the increasement of energy dissipation and decreasement of leakage are analysed.