系统参数对全息法识别噪声源的影响

通过由基尔霍夫边界条件推出的全息重建公式,介绍了近场声全息法进行噪声源识别的原理,并利用空间频域算法对声场进行重建,大大减少了重建过程的计算量,提高了全息重建的效率。同时,分析了计算及测试系统各主要参数对声源识别结果的影响,对重建公式进行了验证,并开发出相应的计算机测试分析软件。结果表明:对重建公式进行修正并根据实际情况充分考虑各参数的影响后,声全息法可对噪声源进行有效识别,为采取噪声控制措施提供可靠依据。

Effect of System Parameters on Noise Identification by Holography

According to the holography reconstruction formula educed from Kirchhoff integral formula, this paper introduces the principle of near-field acoustical holography(NAH)in noise identification and reconstructs the acoustic field by a special arithmetic of dimensional frequency domain in order to reduce the quantity of calculation and improve the efficiency of reconstruction. Meanwhile, the affection of the main parameters of calculating and testing system on the results of noise identification is analyzed and the correctness of the reconstructing formula is validated. As a result, a computer testing and calculating program has been developed. The experimental outcomes indicate that with the revision of the reconstructing formula and taking the influences of the measuring system's parameters into account sufficiently according to the practical conditions, the acoustic holography can be used to distinguish the sources of noises from each other efficiently so to provide the dependable basis for taking the noise control measures.