发动机缸盖罩结构声辐射特性优化分析

Optimization Analysis of Acoustic Radiation Characteristics of Engine Cylinder Head Cover Structures

发动机是船舶动力系统的重要组成部分,是振动噪声的源头之一,发动机缸内噪声通过缸体和缸盖罩向外辐射。以发动机缸盖罩为研究对象,通过有限元建模分析其模态,并进行试验验证。以缸盖罩结构的表面振速和辐射声功率为目标,采用有限元与边界元相结合的方法对缸盖罩结构进行声辐射特性优化设计。研究结果表明:通过结构优化设计,在缸盖罩内部两侧添加等腰三角形加强筋,可使得10Hz~4000Hz频段内发动机缸盖罩辐射声功率平均降低2.10dB(A)。研究结果可为发动机缸盖罩结构的设计提供借鉴。

As an important part of ship power system,engine is one of the sources of vibration noise.The engine cylinder noise radiates outwards through cylinder block and cylinder cover.In this paper,the modals of engine cylinder cover are studied through finite element modeling and experimental verification.With the surface vibration velocity and radiated sound power of the cylinder cover as the target,the optimization design of acoustic radiation characteristic of the cylinder cover structure is conducted by combining finite element method and boundary element method.The results show that the radiated sound power of the engine cylinder cover can be reduced by 2.10 dB(A)in 10 Hz-4000 Hz frequency band in average through structural optimization of adding isosceles triangular stiffeners on both sides of the cover.The results of this research have provided a meaningful reference for the design of engine cylinder cover structures.