内燃机噪声优化对车内声学的影响研究

毛杰,郝志勇

(浙江大学能源工程学系，杭州310027)

摘要：提出了内燃机结构辐射噪声的仿真与优化方法，评价了内燃机噪声优化前后车内噪声的变化。建立了内燃机和前围板的有限元模型，通过模态分析验证了模型的精度。采用柔性多体动力学方法计算了内燃机的振动响应，并结合边界元算法得到了结构辐射噪声。完成了机体的结构优化，通过提升刚度使整体模态频率与激励峰值频率分离，从而降低机体结构响应，减小辐射噪声。搭建了内燃机与前围板的声学耦合模型，计算得到经机体结构优化前后的内燃机辐射噪声通过前围板后进入车内的声功率。结果显示，机体的优化方案大幅降低了其辐射噪声，从而减小了整机的辐射噪声。研究内燃机噪声与车内噪声的传递路径后，发现车内噪声有了明显的下降，从而证实了优化设计的可行性和有效性。

关键词：内燃机噪声；机体优化；前围板；车内噪声；耦合优化

中图分类号:TB532文献标志码：A

基金项目：国家自然科学基金资助项目(51408228);华南理工大学中央高校基本科研业务费专项资金资助(2013ZB0023);中国博士后科学基金资助项目(2013M540656)

收稿日期：2014-01-08修改稿收到日期：2014-03-07

Coupledoptimizationofinternalcombustionengineradiatednoiseandinteriornoise

MAO Jie, HAO Zhi-yong(DepartmentofEnergyEngineering,ZhejiangUniversity,Hangzhou310027,China)

Abstract:A simulation and optimization method for noise reduction of an internal combustion engine was proposed and used to evaluate the interior noise change before and after the engine noise optimization. Finite element models of the engine and dash panel were constructed and validated by modal analysis technology. The flexible multi-body dynamic method was employed to calculate the engine vibration response with which the structural radiated noise was detected via boundary element codes. Then, the optimal design of the engine block was implemented to improve its stiffness and make global modal frequencies apart from excitation peak frequencies, aiming at reducing the structural response and radiated noise. An acoustic coupled model of the engine and dash panel was constructed to calculate the acoustic power transmitted from the engine surface through the dash panel into the interior before and after the block optimization. The results show that the optimal scheme for the block substantially lower the structural radiated noise, as well as that of the engine. After making clear the acoustic transmission path between the engine and interior, it is found that the interior noise can be distinctly reduced, which proves the feasibility and effectiveness of the optimal design.

Keywords:internalcombustionenginenoise;blockoptimization;dash;interiornoise;coupledoptimization

在汽车的行驶过程中，引起车内噪声的因素涉及到每个系统，如车体、发动机、悬架、进气、排气等系统[1]。其中，发动机的振动与噪声与其他系统的结构响应有着密不可分的关系。因此，对发动机的结构实施改进，优化其振动响应与辐射噪声，不仅可以在一定程度上削弱发动机激发其他系统振动的能力，还可以降低发动机传递到车内的噪声量。……