基于多体动力学的发动机噪声预测与轻量化

Noise Prediction and Lightweight of Engine Based on Multi-body Dynamics

为了提高汽车的舒适性和燃油经济性,从发动机振动原理出发,建立发动机多体动力学模型,并通过发动机振动测试试验,验证了该模型的可信度;将发动机多体计算的表面振动结果作为激励源,利用声学理论,建立发动机1m噪声模型,场点的平均声压级仿真值与其试验值最大误差在3.7 dB以内,同样验证了发动机噪声模型的真实性.在整机噪声性能保持不变的前提下,结合拓扑优化提升减重缸体模态,最终使缸体质量减轻3.24 kg,减少率达8.1%.将仿真与试验相结合应用于发动机轻量化技术的开发,可以节约开发成本,缩短开发周期.

In order to improve the comfort and fuel economy of automobiles,a multi-body dynamic model of the engine is established based on the principle of engine vibration,and the reliability of the model is verified through the engine vibration test.Taking the surface vibration results of multi-body calculation of the engine as the excitation source,a 1 m noise model of the engine is established by using the acoustic theory.The maximum error between the simulation value of the average sound pressure level of the field point and its test value is within 3.7 dB,which also verifies the authenticity of the engine noise model.On the premise that the noise performance of the engine remains unchanged,and combined with topology optimization,the mode of the lightweight cylinder body is improved,and the final weight of the cylinder is reduced by 3.24 kg,with a reduction rate of 8.1%.The application of simulation and test in the development of engine lightweight technology can ensure the cost saving of engine development and shorten the development cycle.