径向间隙对刷式密封泄漏特性影响的数值分析  

Numerical Analysis on Influence of Radial Clearance on Leakage Flow Characteristics of Brush Seal

作　　者：戴伟[1] 王炜哲[1] 刘应征[1] 陈汉平[1] 

机构地区：[1]上海交通大学机械与动力工程学院,动力机械与工程教育部重点实验室,上海200240

出　　处：《动力工程学报》2011年第7期507-512,共6页Journal of Chinese Society of Power Engineering

摘　　要：采用计算流体力学方法和多孔介质模型对5种径向间隙布置的刷式密封的泄漏流动特性进行了数值模拟.结果表明：相对于接触式零间隙密封,径向间隙为0.1 mm时的泄漏流量增加了1个数量级,且压比越大,泄漏流量的增幅越大.当间隙增加到0.3-0.4 mm时,从径向间隙通道直接流出的流体达到总泄漏流量的75%-85%.在各种间隙条件下,近背板截面刷丝自由端附近的径向压力梯度达到最大值,促使刷丝区域内的流体沿径向加速流向转子表面并从径向间隙通道流出.Numerical simulation has been performed to study the leakage flow characteristics of brush seal at five different radial clearances using computational fluid dynamics and porous media model.Results show that the leakage flow in brush seal with 0.1 mm radial clearance is almost one order of magnitude higher than in contact seal,and the leakage flow is significantly intensified with rising pressure ratio.For systems with radial clearance in 0.3-0.4 mm,75%-85% of the total leakage is found to be produced directly through the radial clearance.Under various clearance conditions,the maximum radial pressure gradient appears at the free-end of brush seal near the back plate,which makes the fluid in brush region flowing toward the rotor surface in radial direction and subsequently forces it leaking out through the radial clearance.

关 键 词：刷式密封 多孔介质 泄漏特性 径向间隙 

分 类 号：TK263.6[动力工程及工程热物理—动力机械及工程]