基于声品质特性的全地形车排气噪声优化研究

Investigation and Optimization of All Terrain Vehicle Exhaust Noise based on Vehicle Sound Quality Characteristics

NVH水平已成为各大车企关注的重点性能之一,而在竞技娱乐细分领域NVH问题也逐渐被消费者所聚焦,因此提升动力设备的NVH性能已成为产品开发的首要需求。主要研究了搭载单缸自吸发动机的全地形车NVH特性,采用声学有限元法数值模拟技术分析并优化排气消声器结构,完成了消声器快速样件的试制,并通过整车试验验证排气消声器的实际效果与NVH特性。试验发现:怠速工况、定置加速工况条件下,排气口噪声平均降低4.0~7.0 dB(A),耳旁噪声平均降低1.0~2.0 dB(A),且排气口噪声在150~400 Hz频段改善显著,阶次成分H2.5、H3.0、H3.5降低明显,耳旁噪声在150~300 Hz频段降低明显,200~300 Hz共振噪声成分基本消失。排气消声器优化效果明显,整车声品质水平提升显著,为后期深入开发提供理论指导与技术支撑。

NVH issue has become one of the key performances of a vehicle in major enterprises.Even in the area of competitive entertainment,NVH has been noticed and focused by the customers.So improving the NVH performance has become the priority quest in development of an engine.In this paper,we investigated the NVH characteristics of a single-cylinder all terrain vehicle with four wheels in detail.The acoustic finite element method was used in simulating the NVH performance of the exhaust muffler,then modification and optimization of the muffler structure were made accordingly.After the sample prototype being manufactured,the new exhaust muffler was mounted on the vehicle and the validation was proceeded through road testing.The results indicate that the exhaust tail pipe noise has been decreased by 4.0-7.0 dB(A)under the condition of either idle or steady acceleration,while the driver-nearby noise has been attenuated by 1.0-2.0 dB(A).Even more the tail pipe noise in the frequency range of 150-400 Hz has been optimized effectively,as well as the order noise e.g.H2.5,H3.0 and H3.5.For driver-nearby noise,the sound pressure level has been decreased a lot in 150-300 Hz,meanwhile the resonant noise between 200 to 300 Hz has disappeared in result.In conclusion,the exhaust NVH performance has been optimized apparently and the vehicle sound quality has been improved in great degree,which would help give the basis guidance and technical support for development and engineering application.