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针对某空腔低速流动噪声机理问题,发展并应用了脉动压力风洞试验及相阵列风洞试验相结合的方法。脉动压力试验是通过离散点测量方法获得空腔内典型测点的脉动压力统计参数及其功率谱密度函数。脉动压力功率谱存在典型的特征频率,从脉动压力功率谱密度函数中提取空腔流动特征频率,相阵列试验针对空腔流动特征频率所对应的声源进行逐一声源辨识及声源强度评估,声源强度随来流的变化关系与脉动压力变化规律相符合。针对某空腔结构的脉动压力风洞试验及相阵列风洞试验相结合的方法为空腔流动机理认识及空腔流动噪声控制技术研究提供了有效技术手段。
Aiming at the problem of low-speed flow noise in a cavity, a combination of pulsating pressure wind tunnel test and phase array wind tunnel test is developed and applied. The pulsating pressure test obtains the statistical parameters of the pulsating pressure and the power spectral density function of the typical measuring points in the cavity through the discrete point measurement method. The characteristic frequency of pulsating pressure power spectrum is typical, and the characteristic frequency of cavity flow is extracted from the pulsating pressure power spectral density function. The phase array test verifies the sound source corresponding to the characteristic frequency of cavity flow one by one, The relationship between the intensity of sound source and the change of the pulsating pressure is consistent with the change of the pulsating pressure. The combination of pulsating pressure wind tunnel test and phase array wind tunnel test for a cavity structure provides an effective technical means for understanding the cavity flow mechanism and studying the cavity flow noise control technology.