基于MATV的车底高速气流引起的车内噪声计算

Calculation of Vehicle Interior Noise Induced by High-Speed Underbody Airflow Based on MATV Method

鉴于随着后视镜、A柱、天窗等部位的气动噪声源得到有效控制,汽车车底高速气流对车内噪声的影响逐渐凸显,本文中对汽车底部高速气流引起的车内噪声进行研究。首先,应用计算流体力学(CFD)和有限元分析(FEA)相结合的方法计算实车模型车体高速气流引起的车内气动噪声,结果表明,声压激励的传递效率明显高于湍流压力激励,车内噪声随频率升高先增后减,主要集中于100至300 Hz的中低频段。接着,引入模态声传递向量方法(MATV),基于实车模型进行仿真,并与试验和FEA计算结果对比,结果表明,与试验结果很好吻合,而其计算效率比FEA提升了96%。最后,基于MATV方法分别计算了实车模型添加发动机底护板和气坝后车内同一监测点的噪声,总声压级分别降低了2.8和1 dB。

In view of that with the effective control of aerodynamic noise at rear-view mirror,A-pillar,and sunroof,the influence of high-speed underbody airflow on vehicle interior noise becomes gradually prominent,the vehicle interior noise induced by underbody high-speed airflow is studied in this paper.Firstly,the interior noise of Hyundai simple model(HSM)caused by high-speed underbody airflow is calculated by applying computational fluid dynamics,combined with finite element analysis(FEA).The results show that the transfer efficiency of sound pressure excitation is obviously higher than that of turbulent pressure excitation,and the vehicle interior noise first increases and then reduces with the increase of frequency,and mainly concentrated at the low-middle frequency band between 100 and 300 Hz.Then a method of modal acoustic transfer vector(MATV)is introduced and a simulation is conducted on a real vehicle model with its results compared with that of test and FEA calculation,indicating that the results with MATV simulation agrees well with test ones and its calculation efficiency is 96%higher than that with FEA.Finally,an engine bottom closure panel and a frontal air-dam is added on the real vehicle models with corresponding simulations with MATV carried out respectively and the results showing that the total sound pressure level at the same interior monitoring point reduces by 2.8 and 1 dB respectively,compared with that in original real vehicle model.