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1、第40卷第12期哈尔滨工业大学学报Vol140No1122008年12月JOURNALOFHARBININSTITUTEOFTECHNOLOGYDec.2008方柱流致横向振动的CFD数值模拟11,23徐枫,欧进萍,肖仪清(1.哈尔滨工业大学土木工程学院,哈尔滨150090,E2mail:xufeng_hit@163.com;2.大连理工大学土木水利学院,大连116023;3.哈尔滨工业大学深圳研究生院,深圳518055)摘要:为对弹性支撑方柱的流致横向驰振与涡激振动现象进行研究,利用Fluent软件求解Re=500下的粘性不可压流场,方柱振动
2、模型简化为质量-弹簧-阻尼体系,将Newmark-β方法写入用户自定义函数(UDF)来求解柱体运动方程,方柱和流场之间的非线性耦合作用通过动网格实现.考虑了质量比和折合阻尼对方柱振动的影响,结果得到了低频率比下方柱的驰振现象,方柱的最大驰振位移达到215倍边长,观察到方柱由驰振到涡激振动的转化.详细分析不同频率比下柱体的升阻力系数、横向位移特征值和尾流涡结构,获得“拍”和“相位开关”等现象.工程中对自振频率较低的方形结构进行设计时需考虑驰振作用的影响,优先采用不易发生驰振的截面形式.关键词:方柱;驰振;涡激振动;动网格;相位开关中图分类号:TU
3、31113文献标识码:A文章编号:0367-6234(2008)12-1849-06CFDnumericalsimulationofflow2inducedtransversevibrationofasquarecylinder11,23XUFeng,OUJin2ping,XIAOYi2qing(1.SchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin150090,China,E2mail:xufeng-hit@163.com;2.SchoolofCivilandHydrauli
4、cEngineering,DalianUniversityofTechnology,Dalian116023,China;3.ShenzhenGraduateSchoolHarbinInstituteofTechnologyShenzhen518055,China)Abstract:Thegallopingandvortex2inducedvibrationsofanelasticmountedsquarecylinderareinvestigatedinthispaper.TheReynoldsnumberiskeptat500forallc
5、alculations.Theviscousincompressibleflowfieldwascalculatedbythecomputationalfluiddynamics(CFD)codeofFluentsoftware,thenthemotionofsquarecylinderwasmodeledbyaspring2damper2masssystem,andthemotionequationofthecylinderwassolvedbywritingtheNewmark2βmethodintotheUser2Defined2Func
6、tion(UDF),moreover,thenonlinearcouplingbe2tweensquarecylinderandflowfieldwascarriedoutthroughthedynamicmeshtechnique.Resultsshowthatwhentheinfluenceofmassratioandreduceddampingonflow2inducedvibrationistakenintoconsideration,thegallopinginlowfrequencyratioisobserved,themaximu
7、moscillationscanreach215timesofsidelengthundergalloping,andthetransitionfromgallopingtovortex2inducedvibrationisfound.Thenthecharacteristicparametersofliftanddragcoefficient,transversedisplacementandvortexpatterninthewakeofthesquarecylinderindifferentfrequencyratioswerestudi
8、edindetailandthephenomenaof“beat”and“phaseswitch”wereconfirmed.Thustheinflu