挡板结构对刷式密封泄漏流动特性的影响

为研究前后挡板结构对刷式密封压力和流场的影响规律，采用非线性Darcian多孔介质模型，分别建立6种不同前后挡板结构的刷式密封求解模型，通过与相关实验数据对比，验证模型的合理性，采用ANSYS软件对刷式密封进行数值分析，研究不同前后挡板结构下的刷丝束压力和流场分布特性。研究结果表明：压比和挡板结构对刷式密封封严性能起到关键作用；刷式密封的泄漏量随着压比增大而增大，长前挡板结构能够减小泄漏量，基本型和环形腔型后挡板结构的泄漏量基本没有区别，通腔后挡板结构会使泄漏量显著增长；长前挡板结构能够减小刷丝束内压力，后挡板结构对刷式密封的压力分布起到决定作用；通腔后挡板能够消除部分径向压力梯度，提高刷式密封寿命，但会造成泄漏量增长。

Effect of Plate Structure on Leakage Flow Characteristics of Brush Seals

In order to study the influence of the front and back plate structures on the pressure and flow field of the brush seal,the nonlinear Darcian porous medium model was used to establish the brush seal solution models of six different front and back plate structures.The rationality of the model was verified by comparing with the relevant experimental data.The pressure and flow field of the brush seals of six different front and back plate structures were numerically analyzed by ANSYS software.The results show that pressure ratio and plate structure play a key role in the sealing performance of brush seals.The leakage of brush seals increases with the increase of pressure ratio.The long front plate structure can reduce the leakage,and there is no difference in leakage between the basic and annular cavity back plate structures,while the through cavity back plate structure can significantly increase the leakage.The long front plate structure can reduce the pressure in the brush tow,and the back plate structure plays a decisive role in the pressure distribution of the brush seal.The through cavity back plate can eliminate some radial pressure gradient and improve the life of the brush seal.