紊流积分尺度对CAARC模型表面风压特性的影响  

Effects of turbulence integral scale on surface wind pressure characteristics of CAARC model

作　　者：张海程 杜树碧 李明水[1,2] 秦川[1] ZHANG Haicheng;DU Shubi;LI Mingshui;QIN Chuan(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Wind Engineering Key Laboratory of Sichuan Province,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]西南交通大学风工程四川省重点实验室,成都610031

出　　处：《振动与冲击》2022年第9期81-89,106,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(51878580)。

摘　　要：常规风洞不能较好模拟紊流积分尺度,造成模型缩尺比与积分尺度不匹配。采用两种缩尺比CAARC(Commonwealth Advisory Aeronautical Research Council)模型在相应缩尺比的B类风场中进行同步测压试验,研究紊流积分尺度对平均风压系数、脉动风压均方根系数、脉动风压功率谱、风压水平和竖向相关系数、以及风压竖向相干函数的影响。结果表明:平均风压系数受紊流积分尺度影响较小,而脉动风压均方根系数随L_(u)^(x)/D的减小而减小,且脉动风压均方根系数偏小程度随L_(u)^(x)/D偏小程度的增大而增大;迎风面驻点的脉动风压功率谱,在低频区间,由准定常效应控制,基本保持一致,在高频区间,其衰减速度快于脉动风速功率谱,且衰减速度随紊流积分尺度的减小而加快;紊流积分尺度越小,宽面迎风时侧面与背面的脉动风压功率谱越大,迎风面外缘点和背面的漩涡脱落特征更明显;在迎风面,脉动风压水平相关系数和竖向相关系数随着L_(u)^(x)/D的减小而减小;在侧面,宽面迎风时脉动风压水平和竖向相关系数随着L_(u)^(x)/D的减小而增大,窄面迎风时脉动风压水平相关系数随着L_(u)^(x)/D的减小而减小,测点距离较近时,竖向相关系数随着L_(u)^(x)/D的减小而增大,测点距离较远时,竖向相关系数随着L_(u)^(x)/D的减小而减小;在背面,宽面迎风时,随着L_(u)^(x)/D的减小,水平相关系数减小,竖向相关系数增大,窄面迎风时,随着L_(u)^(x)/D的减小,水平相关系数减小,测点距离较近时,竖向相关系数增大,测点距离较远时,竖向相关系数减小;迎风面脉动风压竖向相干函数大于脉动风速相干函数。The conventional wind tunnel can’t better simulate turbulence integral scale to cause mismatch between model scale ratio and integral scale.Here,2 CAARC models with different scale ratios were used to conduct synchronous pressure measurement tests in class B wind field with corresponding scale ratios to study effects of turbulence integral scale on average wind pressure coefficient,root mean square coefficient of fluctuating wind pressure,power spectrum of fluctuating wind pressure,correlation coefficients of horizontal and vertical wind pressures and wind pressure vertical coherence function.The results showed that the average wind pressure coefficient is less affected by turbulence integral scale,while the root mean square coefficient of fluctuating wind pressure decreases with decrease in L_(u)^(x)/D,and the degree to L_(u)^(x)/D smaller side of the root mean square coefficient of fluctuating wind pressure increases with increase in degree to smaller side of L_(u)^(x)/D;in low frequency range,fluctuating wind pressure power spectrum at arrest point on windward surface is controlled by quasi-steady effect and basically remains the same;in high frequency range,its attenuation speed is faster than fluctuating wind speed power spectrum,and the attenuation speed increases with decrease in turbulence integral scale,the smaller the turbulence integral scale,the larger the fluctuating wind pressure power spectrum on side and back during wide surface facing wind,and vortex shedding characteristics on outer edge and back of windward surface are more obvious;on windward surface,horizontal correlation coefficient and vertical correlation coefficient of fluctuating wind pressure decrease with decease in L_(u)^(x)/D;on side surface,when wide surface facing wind,horizontal and vertical correlation coefficients of fluctuating wind pressure increase with decrease in L_(u)^(x)/D,when narrow surface facing wind,horizontal correlation coefficient of fluctuating wind pressure decreases with decrease in L_(u)^(x)/D,when distance

关 键 词：紊流积分尺度 CAARC标准模型 风压分布 风洞试验 

分 类 号：O383[理学—流体力学]