柴油机机体声辐射模态特性分析

本文首先从结构振动模态理论的角度，论述了结构振动与声辐射之间的基本耦合关系，提出了结构声辐射模态的有关理论，用结构的声辐射模态参数来表征结构本身的固有声辐射特性。然后将该理论应用于柴油机机体的声辐射特性分析。利用有限元技术，建立了柴油机机体的动力学模型，并经过理论计算得到机体的模态参数。在此基础上，应用文中提出的声辐射模态理论，对机体进行了声辐射模态参数计算，获得了柴油机机体的声辐射特性，从而为机体的低噪声设计提供了依据

Acoustic Radiation Modal Analysis of Diesel Engine Block

The theory on structural acoustic radiation mode, which is concerned with the fundamental relation between structural vibration and acoustic radiation, is first addressed in this paper. According to the theory, the structural acoustic radiation modal parameters can be used to characterize the inherent acoustic radiation properties of structures. Then, the presented theory is used to analyse the acoustic radiation properties of the diesel engine block. For this purpose, a finite element model of engine block dynamics is established, and then the dynamic characteristics are analyzed theoretically with this model. On the basis, the acoustic radiation modal parameters are calculated and the acoustic radiation properties of the engine block can be obtained, which provide the basis for the low noise engine block design.