采用叉排管束模型的刷式密封刷丝束变形特性研究  

Investigating Mechanical Deformation Characteristics of Bristle Packs of Brush Seals via Staggered Tube Bundle Model

作　　者：宋鹏飞 屈杰 高庆[2,3] 李志刚 李军[1] SONG Pengfei;QU Jie;GAO Qing;LI Zhigang;LI Jun(Institute of Turbomachinery,Xi’an Jiaotong University,Xi’an 71049,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an TPRI Energy Conservation Technology Co.,Ltd.,Xi’an 710054 China;National Key Laboratory of Efficient Coal Electricity and Carbon Capture Utilization and Storage,Beijing 100031,China)

机构地区：[1]西安交通大学叶轮机械研究所,西安710049 [2]西安热工研究院有限公司西安西热节能技术有限公司,西安710054 [3]高效灵活煤电及碳捕集利用封存全国重点实验室,北京100031

出　　处：《西安交通大学学报》2024年第9期48-61,共14页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(52376029)。

摘　　要：采用刷式密封三维叉排管束泄漏流动数值模拟与有限元分析模型相结合的流固耦合方法,研究了刷丝束在气动载荷作用下的变形特性。通过数值求解三维雷诺时均Navier-Stokes(RANS)方程组和SSTk-ω湍流模型,获得了刷丝束气动载荷,刷丝束有限元接触模型综合考虑了刷丝束内部存在的摩擦接触力。研究表明:随着压比的增大(1.5~3.0),刷式密封泄漏流量系数增大的趋势逐渐减缓,第5~9排刷丝承受压差占比从60%增长至70%,转速对刷式密封泄漏流场影响微弱。刷丝所受周向和径向气流力大小相当,二者合力方向与刷丝垂直,轴向气流力则是周向、径向气流力的13.6~18倍。较大轴向气流力使刷丝在围栏高度区域向下游发生轴向弯曲,压比为1.5、2.0、2.5和3.0时,刷丝束最大轴向变形量分别为0.077、0.096、0.114和0.130mm。较小周向、径向力以及后排刷丝与后夹板之间较大摩擦接触力,使刷丝周向和径向变形量很小。刷丝束所受轴向气流力与法向气流力的比值可用于分析刷丝周向变形滑移。所建立的基于刷式密封叉排管束模型的流固耦合方法为分析刷丝束变形特性提供了研究途径。The deformation characteristics of bristle packs under aerodynamic load are investigated using a fluid-structure coupling method that combines numerical simulation of leakage flow of a three-dimensional staggered tube bundle with a finite element analysis model.The aerodynamic loads of the bristle pack are derived from the numerical solution of the three-dimensional Reynolds averaged Navier-Stokes(RANS)equations using the SST k-ωturbulence model.The friction contact force within the bristle pack is comprehensively considered in the finite element contact model.Results show that as the pressure ratio increases(1.5 to 3.0),the trend of the increase in the leakage flow coefficient of the brush seal gradually slows down,and the pressure drop across the 5th to 9th row of bristles accounting for the overall pressure differential increases from 60%to 70%.The rotational speed exhibits minimal influence on the leakage flow field of the brush seal.Circumferential and radial forces are nearly equal in magnitude,with the direction of the resultant force perpendicular to the bristle.The axial flow force is 13.6—18 times greater than the circumferential/radial force.The large axial airflow force causes the bristle to bend axially downstream in the fence height region.When the pressure ratio is 1.5,2.0,2.5 and 3.0,the maximum axial deformation of the bristle is measured at 0.077,0.096,0.114,and 0.130 mm,respectively.Minimal circumferential and radial deformation of the bristle pack is observed due to the small circumferential/radial forces and the large frictional contact force between the bristle and the backing plate.The ratio of axial aerodynamic force to the normal force of the bristle pack can be used to analyze the circumferential slip deformation of bristle rows.The fluid-structure interaction analysis method based on the staggered tube bundle model of the brush seal provides a research approach for analyzing the mechanical deformation of the bristle pack.

关 键 词：刷式密封 刷丝束 三维叉排管束 变形 

分 类 号：TK474.7[动力工程及工程热物理—动力机械及工程]