摘要
采用基于非线性Darcian多孔介质模型的三维Reynolds-Averaged Navier-Stokes(RANS)方程耦合Finite Element Method(FEM)接触模型的数值方法,建立了考虑了泄漏流体气动力、刷丝间摩擦力和刷丝与前后夹板间的相互作用的刷式密封刷丝变形及接触力特性的预测模型。对比分析了单级和两级刷式密封的刷丝变形量及其与转子面的法向接触力和摩擦力随压比的变化特性,探究了刷丝直径、刷丝倾斜角和干涉量对刷丝与转子表面接触力的影响规律。结果表明:压比由1.1变化到4.0时,单级和两级刷式密封的刷丝变形量、刷丝与转子面的法向接触力和摩擦力均随压比的增大而增大;在相同压比条件下,两级刷式密封上游级和下游级刷丝与转子面的法向接触力较单级刷式密封分别可降低55%和32%;刷丝与转子面的法向接触力和摩擦力随刷丝直径、刷丝倾斜角和刷丝束与转子面干涉量的增大而增大。当刷丝直径小于0.08 mm,干涉量小于0.1 mm,刷丝倾斜角在30°～45°之间时,可有效降低刷丝与转子间的法向接触力和摩擦力。
The prediction model of bristle deformation and contact force characteristics of brush seals with consideration of leakage flow aerodynamic force, frictional force among bristles and interaction between the bristle pack and the front and backing plate was presented in this work. Three-dimensional Reynolds-Averaged Navier-Stokes(RANS) based on non-linear Darcian porous medium model combined with Finite Element Method(FEM) contact model was applied to analyze the bristle deformation and contact force characteristics of brush seal. Variations of bristle deformation, normal contact force and frictional force with pressure ratio are compared between the single and two-stage brush seal. Effects of bristle diameter, bristle lay angle and bristle interference on contact force between bristle pack and shaft surface were investigated. The results show that the bristle deformation, normal contact force and friction force of both single and two-stage brush seal increase with the increase of pressure ratio ranged from 1.1 to 4.0. Normal contact force of upstream and downstream bristle pack in two-stage brush seal are reduced by 55% and 32% respectively compared with the single brush seal at the same pressure ratio. Normal contact force and frictional force between bristle pack and shaft surface increases with the increase of the bristle diameter, lay angle and interference. The normal contact force and frictional force between the bristle pack and shaft surface of brush seal can be effectively reduced when the bristle diameter and interference is less than 0.08 mm and 0.1 mm in respective, as well as the bristle lay angle is designed from 30° to 45°.
作者
刘璐园
张元桥
李军
Liu Luyuan;Zhang Yuanqiao;Li Jun(Institute of Turbomachinery,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《燃气轮机技术》
2019年第1期1-7,共7页
Gas Turbine Technology
基金
国家重点研发计划(2017YFB0601804)
关键词
刷式密封
刷丝变形
接触力特性
数值模拟
brush seal
bristle deformation
contact force characteristics
numerical simulation
