4DW93柴油机表面辐射噪声仿真研究

Simulation study on surface radiation noise of 4DW93 diesel engine

为对4DW93柴油机的整体噪声做一个具体的评价,并为下一步的降噪提供一定的依据,建立了该柴油机的仿真模型,利用有限元法结合边界元法对其进行振动噪声仿真分析,通过9点测量法模拟计算了整机总噪声声压级,计算得出了该柴油机的表面振动速度分布、辐射噪声频谱、声压分布以及总噪声声压级。计算结果表明:该柴油机的辐射噪声主要来源于油底壳、齿轮室盖、飞轮壳,应优先着重考虑这三个部位的降噪措施;改进内燃机的悬置机构,优化油底壳、飞轮壳和齿轮室盖以及加强机体裙部的刚度,可以作为降噪的主要手段。该柴油机总噪声声压级为108.99dB,基于有限元计算结果,对油底壳进行了结构优化,优化后整机总噪声声压级降低到了107.49dB。

To evaluate the noise of the diesel engine 4DW93 and provide the basis for noise reduction,a boundary element model of the diesel engine has been built and finite element software is used to analyze the noise of the engine.Surface vibration velocity distribution,radiation noise spectrum,sound pressure distribution and total noise level are calculated by 9points method.The calculation results obtained show that the total SPL（sound pressure level）is 108.99dB;the main sources of the noise of the diesel engine are oil sump,gear chamber cover and flywheel housing,these three parts should be prior;improving the suspension mechanism of the internal combustion engine,optimizing the oil sump,flywheel housing and gear chamber cover and strengthening the rigidity of the skirt of the engine body can be used as the primary means of noise reduction.After optimizing the oil sump structure due to the FEM calculation results,the SPL of the engine decreases to 107.49 dB.