CAJ | 학술논문

在重力式低速水洞中完成了湍流边界层流场测量，并分别利用自相关方法和小波分析方法，对对数律区中一测点处的速度信号进行了分析。结果表明，自相关方法对于平均猝发周期的检测精度较高；小波分析方法可用于猝发事件的提取，但对平均猝发周期的检测精度较低。为此，进一步提出了一种同时基于自相关方法和小波分析方法的壁湍流猝发事件快速检测与提取方法，并总结了该方法的具体实施步骤。与原方法相比，该方法既能够精确检测湍流平均猝发周期，又能够提高猝发事件的提取精度。
재중력식저속수동중완성료단류변계층류장측량，병분별이용자상관방법화소파분석방법，대대수률구중일측점처적속도신호진행료분석。결과표명，자상관방법대우평균졸발주기적검측정도교고；소파분석방법가용우졸발사건적제취，단대평균졸발주기적검측정도교저。위차，진일보제출료일충동시기우자상관방법화소파분석방법적벽단류졸발사건쾌속검측여제취방법，병총결료해방법적구체실시보취。여원방법상비，해방법기능구정학검측단류평균졸발주기，우능구제고졸발사건적제취정도。
Flow field measurement of turbulent boundary layer was accomplished in a gravitational low -speed water tunnel set up by us .The velocity signal of a test point in logarithmic layer is analyzed respectively with two methods ( autocorrelation method and wavelet transform method ) , and the results and their analysis demonstrate preliminari-ly that the autocorrelation method has high precision for the detection of average burst period , while the wavelet transform method can be used to extract burst events but with low precision .Consequently , an improved method with high precision and efficiency is put forward based both on autocorrelation and wavelet transform , and the spe-cific implementation steps are summarized in section 3 of the full paper .Compared with old methods , our improved method can indeed extract burst events of wall turbulence both accurately and efficiently .