圆柱尾流中眼镜蛇探针与热线的性能对比  

Comparison of the performance of cobra probe and hotwire in circular cylinder wake

作　　者：王汉封[1,2] 李卓峰 林祥德[1] 

机构地区：[1]中南大学土木工程学院,长沙410075 [2]中南大学高速铁路建造技术国家工程实验室,长沙410075

出　　处：《实验流体力学》2014年第5期104-110,共7页Journal of Experiments in Fluid Mechanics

基　　金：国家自然科学基金(51108468)

摘　　要：在雷诺数为7200的圆柱尾流中对眼镜蛇探针与热线的测量结果进行了详细对比,主要包括:时均速度、雷诺应力、概率密度函数、自相关函数和能谱等。从对比结果可以发现眼镜蛇探针数据的拒绝率随湍流度增大而增大,但在本实验中其对时均测量结果无明显影响。尽管眼镜蛇探针数据有效率在95%以上,但相对于热线其明显高估了雷诺应力。尤其是主雷诺剪切应力u*v*,眼镜蛇探针与热线测量结果的差异要显著大于两者在雷诺正应力上的测量差异。由于无法反映高频随机脉动的影响,眼镜蛇探针所测信号自相关系数的周期性明显强于热线。眼镜蛇探针对速度u和v的响应存在区别,使得两者能谱在惯性子区内有显著差异,不能像热线一样反映出惯性子区内小尺度湍流的各向同性。The performance of cobra probe and hotwire is compared in a circular cylinder wake at the Reynolds number of 7200,including time-averaged velocity,Reynolds stresses,probability density functions,auto-correlation coefficients and spectra.Based on the experimental results,it is found that the rejection rate of cobra probe increases with turbulence intensity.However,its effect on the time-averaged results is negligibly small.Although the acceptability rate of cobra probe is higher than 95%,it over estimates the Reynolds stresses compared to hotwire.Particularly,for the main Reynolds shear stress u＊v＊,the difference of measurements between cobra probe and hotwire is significantly larger than those for the Reynolds normal stresses.Since cobra probe can not capture high frequency fluctuation,the auto-correlation coefficients of velocities present stronger periodicity relative to that of hotwire.The responses of cobra probe are different for u and v,resulting in significant difference in their spectra in the inertial sub-range,and thus it can not reveal the local isotropy of small scale turbulence in the inertial sub-range.

关 键 词：眼镜蛇探针 热线 性能对比 湍流统计量 能谱 

分 类 号：V211.752[航空宇航科学与技术—航空宇航推进理论与工程]