流体诱发换热器管束弹性不稳定性的数值模拟  

Numerical Simulation of Fluid-Elastic Instability in Heat Exchanger Tube Bundles

作　　者：程瑞佳 张亚楠[1] 肖清 陈小阁 刘宝庆[1] CHENG Ruijia;ZHANG Yanan;XIAO Qing;CHEN Xiaoge;LIU Baoqing(Institute of Process Equipment,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学化工机械研究所,浙江杭州310027

出　　处：《轻工机械》2018年第3期36-40,45,共6页Light Industry Machinery

基　　金：国家自然科学基金项目(21776246)

摘　　要：针对常规换热器频发的振动破坏现象,课题组基于动网格技术和双向流固耦合方法,建立了流体诱发管束振动的三维数值模型。采用数值模拟对实验难以获得的管束振动轨迹进行了补充;研究了管束发生流体弹性不稳定性时主振方向的变化;分析了管子位置的分布对振动的影响;探究了管束的排列方式和节径比对流体弹性不稳定性的影响。结果显示:流体弹性不稳定性先发生在曳力方向,后发生在升力方向;位于边缘的管子的振幅大于中间管子的振幅;在4种排列方式的管束中,发生流体弹性不稳定性从难到易依次为正方形、正三角形、转置正方形、转置正三角形;在一定的范围内,节径比越小,越易于发生流体弹性不稳定性。课题组对换热器管束在模拟方面的研究可对工程应用起到一定的指导作用。Aiming at frequently occurred vibration damage problems of conventional heat exchangers,based on dynamic mesh technique and two-way fluid-structure interaction,a three-dimension numerical model of flow-induced vibration was established.The vibration trajectory of tube bundles, which were obtained difficultly in the experiment, were supplemented by numerical simulation.The change of the main vibration direction in the fluid-elastic instability of the tube bundle was studied.The influence of tube position on vibration was analyzed.The effects of configuration and pitch-to-diameter ratio of tube bundles on fluid-elastic instability were investigated.The results show that the fluid-elastic instability first occurs in the drag direction,and then occurs in the lift direction.The amplitude of the tube located at the edge is larger than that of the middle tube.In the four kinds of arrangements of the tube bundles,the occurrence of fluid-elastic instability from difficult to easy as follows： normal square,normal triangular,rotated square and rotated triangular.In a certain range,the fluid-elastic instability is more prone to occur with the decrease of pitch-to-diameter ratio.The study on the simulation of heat exchanger tube bundles plays a certain guiding role in engineering application.

关 键 词：动网格 流体弹性不稳定性 双向流固耦合 振动轨迹 

分 类 号：TK172.4[动力工程及工程热物理—热能工程]