汽油-天然气双燃料发动机噪声粗糙度分析.pdf

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汽车工程
2015年(第37卷)第3期
Automotive Engineering
2015(Vol.37)No.3
2015058
汽油一天然气双燃料发动机噪声粗糙度分析
毛杰,邡志勇,张庆辉,郑旭
(浙江大学能源工程学系,杭州310027)
摘要]鉴于声品质客观评价中,噪声粗糙度算法尚未标准化,本文中提出了改进的 Aures粗糙度算法
MARA)。选取最大转矩转速(3800r/min)为研究工况,进行了某汽油一天然气双燃料发动机的声学性能台架试
验。结果表明,燃用汽油时两个测測点的声学响应均大于燃用天然气时的声学响应,整机辐射声功率级分别为106.2
和103.7dB(A)。但人耳主观感觉却是燃用天然气时的噪声粗糙度比燃用汽油时大。采用MARA客观评价该发动
机的噪卢粗糙度的结果显示,燃用天然气时测点1和测点2的噪声总粗糙度分别比燃用汽油时大12.2%和4.3%
间接验证了MARA客观评价更接近于人耳主观感觉。
关键词:压缩天然气发动机;汽油机;噪声粗糙度;改进的 Aures粗糙度算法
An Analysis on the Noise Roughness of a Gasoline/CNG Dual Fuel Engine
Mao Jie, Hao Zhiyong, Zhang Qinghui & Zheng Xu
Department of Energy Engineering, Zhejiang University, Hangzhou 310027
L Abstract] In view of that the noise roughness algorithm has not been standardized in sound quality objective
evaluation, a modified Aures roughness algorithm (MARA is proposed in this paper. An acoustic performance
bench test on a gasoline/natural gas dual fuel engine is conducted at its maximum torque rotating speed of 800r/
min. The results indicate that the acoustic responses at two measuring points when fueling gasoline are higher than
that when fueling natural gas, and the radiated sound power level of whole engine with different fuels are 106. 2db
and 103. 7db respectively. But the subjective perception of human ears is just the opposite, i. e. the noise rough
ness of engine when fueling natural gas is higher than that when fueling gasoline. The results of objective evaluation
for engine noise roughness with MARA algorithm show that the overall noise roughness of measuring point I and 2
when fueling natural gas are 12. 2% and 4. 3%o higher than that when fueling gasoline respectively, indirectly vali
dating that MARA objective evaluation is closer to the subjective hearing sensation of human ears
Keywords: CNG engine; gasoline engine; noise roughness; modified Aures roughness algorithm
准化。比如,基于等响度曲线的 Zwicker响度模型已
前言
被收入ISO532B中;尖锐度模型也可在多个国家标
准中查阅,如德国标准DIN45692?。
心理声学的研究背景之一是试验测得的声学性
在工程中,通常认为A计权声压级(或声功率
能参数(如声压、声强等)已经无法直接反映人耳的级)与人耳的听觉较为接近,可用来评价噪声的品
听觉感受。因此,学者们开展了声激励与人耳听觉质。然而,它不能反映一些重要的声学性能,如噪声
之间对应关系的研究,提出了定量表示该关系的心随时间的波动。噪声的时域波动可以基于粗糙度、
理声学参数,如响度、尖锐度、粗糙度和抖动度等。音调、抖动度等声品质客观参数,描述人耳对声音信
其中响度和尖锐度的计算模型已经被广泛接受并标号瞬时变化的感觉,与声音的调制频率、调制比等参
*国际科技合资项目(2007DFB50150-2)资助。
原稿收到日期为2013年6月14日,修改稿收到日期为2013年9月28日。