一种基于EMD的低湍流度信号处理分析方法

发布时间：2018-03-10 21:40

本文选题：低湍流度　切入点：经验模式分解　出处：《实验流体力学》2016年05期 　论文类型：期刊论文

【摘要】：采用热线风速仪在3座典型低速风洞中进行了流场湍流度测量,这3座低速风洞包括1个低湍流风洞、1个常规闭口风洞和1个开口射流风洞。针对湍流信号通常受噪声干扰的问题,在湍流度值处理中引入了经验模式分解(EMD)自适应滤波和HHT时频谱分析方法。将EMD方法与其他几种湍流度值处理方法进行了比较,包括带通滤波方法(BP)、电磁噪声解耦方法(ENC)和高通惯性衰滤波方法(HPIA)。采用EMD方法测得低湍流风洞的湍流度值,在流场速度30~100m/s的范围内小于0.05%。采用HHT方法完成了脉动速度信号的时频分析,分析发现开口风洞试验段的脉动速度HHT时频谱有突出的低频信号。所构建的EMD自适应滤波器可以有效控制噪声对热线输出信号的影响,是一种有效的低湍流度信号处理方法。
[Abstract]:The flow field turbulence was measured in three typical low speed wind tunnels with a hot wire anemometer. These three low speed wind tunnels include a low turbulence wind tunnel, a conventional closed wind tunnel and an open jet wind tunnel. The empirical mode decomposition (EMD) adaptive filter and the HHT time-frequency analysis method are introduced in the turbulence scale processing. The EMD method is compared with several other turbulence degree processing methods. It includes band-pass filtering method, electromagnetic noise decoupling method (ENC) and high-pass inertial attenuation filtering method (HPIAA). The turbulence degree of low turbulence wind tunnel is measured by EMD method. In the range of 30 ~ 100 m / s of velocity of flow field, the time-frequency analysis of pulsating velocity signal is accomplished by using HHT method. It is found that there is a prominent low frequency signal in the frequency spectrum of pulsating velocity HHT in the open wind tunnel test section. The EMD adaptive filter can effectively control the effect of noise on the hot wire output signal and is an effective signal processing method with low turbulence degree.
【作者单位】：中国空气动力研究与发展中心设备设计及测试技术研究所;
【分类号】：V211.74

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