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ID:32449423
大小:1.13 MB
页数:8页
时间:2019-02-05
《对随机风作用下高速列车的非定常气动载荷》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、学兔兔www.xuetutu.com第48卷第20期机械工程学报Vl01.48NO.2O2012年10月JOURNAL0FMECHANICALENGINEERING0ct.2012DoI:10.3901/JME.2012.20.113随机风作用下高速列车的非定常气动载荷木于梦阁张继业张卫华(西南交通大学牵引动力国家重点实验室成都610031)摘要:为研究随机风作用下高速列车的非定常气动载荷,基于COOPER理论和谐波叠加法计算随高速列车移动的点的脉动风,分析车速和平均风速对量纲一功率谱密度的影响。采用计算流体动力学方法数值计算气
2、动载荷系数随侧偏角的变化规律,研究随机风作用下高速列车非定常气动载荷的计算方法,并推导出非定常气动载荷的概率分布特性。通过仿真分析车速为200~400km/h,平均风速为t0~35m/s时的脉动风和非定常气动载荷发现,量纲一功率谱密度随车速的增加往高频部分移动,平均风速的变化对其影响较小;平均风速对脉动风速的影响大于车速对脉动风速的影响;当考虑侧偏角的变化时,计算得到的非定常气动载荷的波动增大;采用准定常法和改进准定常法计算得到的非定常气动载荷具有随机过程的遍历性,而采用权重函数法及改进权重函数法计算得到的非定常气动载荷不具有随
3、机过程的遍历性。关键词:脉动风非定常气动载荷概率分布功率谱密度遍历性中图分类号:U292UnsteadyAerodynamicLoadsofHigh—-speedTrainsunderStochasticWindsYUMenggeZHANGJiyeZHANGWeihua(TractionPowerStateKeylaboratory,SouthwestJiaotongUniversity,Chengdu610031)Abstract:Tostudytheunsteadyaerodynamicforcesofhigh-speedt
4、rainsunderstochasticwinds,thefluctuatingwindsofamovingp0shiftingwithhi曲-speedtrainsarecalculatedinthispaperbasedOnCOOPERtheoryandharmonicsuperpositionmethod.Theeffectsoftrainspeedsandaveragewindspeedsonthedimensionlesspowerspectraldensityareanalyzed.Thecomputationalf
5、luiddynamicsmethodisusedtoobtaintheaerodynamicl0adcoe伍cientsatdirentslipangles.Theunsteadyaerodynamicl0adcalculationmethodsforhigh-speedll-ainsunderfluctuatingwindsarestudiedandtheprobabilitydistributionofunsteadyaerodynamicloadsisderived.Thefluctuatingwindsandtheuns
6、teadyaerodynamicloadsofhigh-speedtrainsundertrainspeedsof20O-4O0km/h.andaveragewindspeedsof10—35m/sarecalculatedandtheresultsshowthatthedimensionlesspowerspectraldensityismovingtoahigherfrequencyrangewiththeincreaseoftrainspeeds,whiletheaveragewindspeedshavelittleefe
7、ctonit.111eaveragewindspeedshaveamoresignificantimpactonfluctuatingWindsthantheaveragetrainspeedsdo.Whenconsideringfluctuationoftheslipangles,fluctuationoftheunsteadyaerodynamicloadsincreases.Theunsteadyaerodynamicloadsobtainedusingthequasi-steadymethodandthemodified
8、quasi-steadymethodhavethecharacteristicofe~odicityofrandomprocesses.弭theonesobtainedusingtheweightingfunctionmethodandthemodifiedwe
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