旋流对刷式封严刷丝变形影响的流固耦合研究  

Fluid-Structure Interaction Study on the Effect of Inlet Swirl on the Brush Seal Bristle Deflections

作　　者：孔晓治 黄天硕 刘育心 陈化 陆华伟 KONG Xiao-Zhi;HUANG Tian-Shuo;LIU Yu-Xin;CHEN Hua;LU Hua-Wei(School of Naval Architecture Ocean Engineering,Dalian Maritime University,Dalian 116026,China;School of Marine Engineering,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]大连海事大学船舶与海洋工程学院,大连116026 [2]大连海事大学轮机工程学院,大连116026

出　　处：《工程热物理学报》2021年第5期1224-1232,共9页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.52006021);辽宁省自然科学基金资助项目(No.2020-BS-069)。

摘　　要：采用刷式封严三维流动数值模拟与刷丝变形力学分析模型相结合的流固耦合方法,研究了刷丝与转子有/无径向间隙条件下,进口旋流对刷丝变形运动及刷式封严泄漏特性的影响规律。该方法能够模拟刷丝束内部细密结构的流动细节,变形求解综合考虑了气流气动力、刷丝与转子、刷丝与后挡板以及刷丝间接触力作用。研究表明,进口旋流会严重影响上游刷丝的变形运动,并且随旋流增大,刷丝变形加剧;当刷丝所受法向力与轴向力的比值大于某一临界值时,刷丝将发生周向滑移气动弹性失稳、密封性能下降。相比于无密封间隙情况,刷丝与转子密封间隙为0.2 mm时,刷式封严能够承受更高的旋流速度,也即具有更高的稳定性。A combined 3 D CFD and structural modelling of brush seals was carried out to investigate the effects of inlet swirl on the bristle deflections and leakage characteristics with/without radial clearance between bristle pack and rotor.The coupled model can capture the flow details inside the bristle pack.Also,the mechanical model comprehensively takes the aerodynamic forces generated by CFD,bristle-rotor contact,bristle-backing plate contact and bristle-bristle contact into consideration.Results show that the inlet swirl has a significant impact on the upstream bristle deflections,and with the increase of swirl,the deflection is serious.The increasing swirl will lead to the force normal to the bristle increases.At a critical ratio of bristle normal force to axial force,the circumferential slip of the upstream bristle row was observed.As a result,the aeroelastic stability and sealing performance of brush seal decrease.Comparing to the case without radial clearance,when there is a radial clearance(c=0.2 mm)between the bristle pack and rotor,the brush seal can tolerate higher swirl,that is,it has higher stability.

关 键 词：刷式封严 流固耦合 刷丝变形 气动失稳 

分 类 号：TK123[动力工程及工程热物理—工程热物理]