CAJ | 학술논문

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。
재뢰낙수위7200적원주미류중대안경사탐침여열선적측량결과진행료상세대비，주요포괄：시균속도、뢰낙응력、개솔밀도함수、자상관함수화능보등。종대비결과가이발현안경사탐침수거적거절솔수단류도증대이증대，단재본실험중기대시균측량결과무명현영향。진관안경사탐침수거유효솔재95％이상，단상대우열선기명현고고료뢰낙응력。우기시주뢰낙전절응력u*v*，안경사탐침여열선측량결과적차이요현저대우량자재뢰낙정응력상적측량차이。유우무법반영고빈수궤맥동적영향，안경사탐침소측신호자상관계수적주기성명현강우열선。안경사탐침대속도u화v적향응존재구별，사득량자능보재관성자구내유현저차이，불능상열선일양반영출관성자구내소척도단류적각향동성。
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.Particu-larly,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.