民机适航审定噪声的纯音修正方法

An investigation of tone correction method of noise level in civil airplane airworthiness certification

大型运输类民机适航合格审定噪声水平采用有效感觉噪声级来评定,引入纯音修正因子来考虑噪声频谱不规则性对人主观感觉的影响,而纯音修正因子的计算受试验环境、测试系统特性、数据计算精度、纯音频带分割、数据调整方法和虚假纯音等影响,应在计算中给予考虑.根据适航规章要求,对适航审定噪声的纯音修正方法进行了研究.通过分析纯音修正因子计算的影响因素,基于"CCAR-36"基本方法提出了调整后的计算方法和步骤,并对某型民机适航审定试验的噪声进行了纯音修正分析.结果表明,合理地考虑各影响因素对实现纯音修正因子准确计算具有重要意义,该方法能可靠地应用于纯音修正因子计算,提高了纯音修正因子和有效感觉噪声级计算的准确度,可为国产大型民机噪声适航审定提供有益参考.

Tone correction factor is made to account for the human subjective response to the presence of spectral irregularities when calculate the effective perceived noise level (EPNL) in civil airplane noise airworthiness certification. But the impacts that affect tone correction factor calculation method should be considered, including test environment, test system characteristics, accuracy of data calculation, band sharing adjustment of tone, data adjustment method, false tone and so on. Considering the influence factors and the provisions of airworthiness regulation, tone correction method of transport category large airplanes’ noise level is investigated. And a modified method which includes integrated practical procedures is presented. Then the method is applicable to calculate and analyze the tone correction factors of a certain civil airplane’s airworthiness certification noise tests. The results show that the influence factors have significant impact on tone correction factors’ calculation procedures. This method can be used to obtain tone correction factor precisely and conveniently and it can provide a guidance to domestic civil airplane noise airworthiness certification.