薄叶气封流场结构与密封、扭矩特性的数值研究

采用CFX商业软件,数值模拟了薄叶气封内的三维流动,分析了薄叶气封的流场结构和密封特性以及扭矩随转速和抬起量的变化。结果表明,由于薄叶间距很狭窄,壁面对气体的黏性阻抗大于气流的膨胀加速,气体同时降低速度与密度,泄漏流量明显减小。此外,转子转数与薄叶抬起量的变化几乎不影响泄漏量。在转子转数一定时,薄叶上抬量愈小,转子承受的摩擦扭矩愈大。而当薄叶上抬量一定,转子转数增加,摩擦扭矩增大。

Numerical Study on the Flow Filed Structure and Seal,Torque Characteristics of Leaf Sealing

Numerical simulation of the 3D flow inside the leaf seal has been taken by commercial software CFX,flow structure and sealing characteristics of leaf seal,and torque change with rotational speed and lift rate was analyzed.The result shows because the clearance between each leaf is small,viscous impedance of wall to gas is larger than the expansion accelerate of gas,both velocity and density of gas is decreased,leakage rate is reduced evidently.On the other hand,rotational speed of rotor and lift rate of leaf can hardly influence leakage rate.When the rotational speed of rotor is defined,the smaller the lift rate of leaf,the larger thefriction torque puts on the rotor.While the lift rate of leaf is defined,the friction torque increases with the rotational speed of rotor increasing.