A Study on Generation Mechanisms of Combustion Induced Noise in Diesel Engine

柴油机燃烧噪声产生机理的研究

• 批准号: 04650192
• 负责人: KOJIMA Naoya
• 金额: $ 1.28万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650192/
• 关键词: Internal Combustion Engine; Noise; Combustion Impact; Coherence Analysis; Vibration Intensity; Transfer Function

In diesel engine structure, there are three main excitation sources whichare strongly related with the combustion impact, that is, (1) gas excitation caused by rapid rise of cylinder pressure, (2) shocks caused by striking the elements at bearings or gears, (3) impulsive excitations caused by piston-slaps. The multi-coherence analysis between impulsive responses caused by these three excitations and the engine noise was examined to clarify each contribution to the total engine noise. In this analysis, the residual spectrum method was employed remove the influences of other excitations.It was clarified through these analyzes that (1) had a large coherence with the low and middle frequency components, beside (2) and (3) had a distinguished corelation with the high frequency component of the engine noise. These methods were applied to a small sized engine, and it was clarified that the predominant cause of the acceleration noise of engine was pistonslaps.The influence of lubricating oil film in bearings to combustion induced noise was investigated considering the temperature and feed of oil, the pressure of oil film, and the displacement of crank shaft. From these experiments, it became clear that the contribution of lubricating oil in bearings to the combustion induced noise of engine was atmost 2dB in over-all value.Vibration intensity measurement was proposed as a means for the identification of impact sources in an engine structure. The destributions of the dircetion of intensity vectors were shown on each outer wall of a diesel engine. Through these measurements, the transmission paths of combustion impact were clarified.

在柴油机结构中，与燃烧冲击密切相关的激励源主要有3种，即（1）气缸压力快速升高引起的气体激励，（2）轴承或齿轮上的元件撞击引起的冲击，（3）活塞拍打引起的脉冲激励。检查这三种激励引起的脉冲响应与发动机噪声之间的多重相干分析，以阐明每种对发动机总噪声的贡献。分析中采用残差谱法消除了其他激励的影响。通过分析可以看出(1)与发动机噪声的低频、中频成分有较大的相关性，(2)、(3)与发动机噪声的高频成分有显着的相关性。将这些方法应用于小型发动机，明确了发动机加速噪声的主要原因是活塞敲击声。综合考虑油温、供油量、油膜压力、曲轴位移等因素，研究了轴承润滑油膜对燃烧噪声的影响。从这些实验中可以清楚地看出，轴承中的润滑油对发动机燃烧引起的噪声的贡献总体上最多为2dB。振动强度测量被提出作为识别发动机结构中的冲击源的一种手段。强度矢量方向的分布显示在柴油机的每个外壁上。通过这些测量，明确了燃烧影响的传递路径。

项目成果

Naoya KOJIMA, Jian Yu CHANG and Nobuyuki MII: "Application of Envelope Vibration Intensity Measurement to a Diesel Engine Structure" Proc.Asia-Pacific Vib.Conf.'93. 1072-1077 (1993)

Naoya KOJIMA、Jian Yu CHANG 和 Nobuyuki MII：“包络振动强度测量在柴油机结构中的应用”Proc.Asia-Pacific Vib.Conf.93。

Hai ZHOU, Naoya KOJIMA and Masana KATO: "Vibration Intensity Measurement Using Three Accelerometers" Trans.JSME. 59-558(in Japanese). 445-451 (1993)

Hai ZHOU、Naoya KOJIMA 和 Masana KATO：“使用三个加速度计进行振动强度测量”Trans.JSME。

Haruo IXUMI, Jian Yu CHANG and Naoya KOJIMA: "A Study on Combustion Induced Noise of Diesel Engine (Effects of Lubricating Oil in Bearing)" Tech. Rep. Yamaguchi Univ.(Faculty of Engineering). 44-1(in Japanese). 19-26 (1993)

Haruo IXUMI、Jian Yu CHANG 和 Naoya KOJIMA：“柴油机燃烧引起的噪声的研究（轴承中润滑油的影响）”技术。

Naoya KOJIMA and Takashi IDHIKAWA: "An Analysis of Acceleration Noise Using Coherence Technique in Small Sized Four-Stroke Gasoline Engine" Proc.JSME. 945-1(in Japanese). 144-146 (1994)

Naoya KOJIMA 和 Takashi IDHIKAWA：“小型四冲程汽油发动机中使用相干技术的加速噪声分析”Proc.JSME。

Jian Yu CHANG, Hai ZHOU and Naoya KOJIMA: "The Measurement of Enverope Vibration Intensity to Identify the combustion Impact Transmission in Diesel Engine" Proc.Inter-Noise'94. (to be published). (1994)

Ken Yu Chang、Hai ZHOU 和 Naoya KOJIMA：“测量包络振动强度以识别柴油机燃烧冲击传递”Proc.Inter-Noise94。