基于LBM-FE-SEA方法汽车风窗噪声数值模拟研究

Numerical Simulation Research of VehicleWindshield Noise Based on LBM-FE-SEA Method

为研究某车型风窗噪声,根据格子波尔兹曼(Lattice Boltzmann,LBM)方法获得高速行驶工况下车身表面各监测点处的1/3倍频程声压级及平均输入激励。采用混合有限元-统计能量分析(Finite Element-Statistical Energy Analysis,FE-SEA)方法对该车型车内噪声进行输入激励下的数值模拟,得到驾驶员耳旁声压级结果,并与实车道路试验比较,验证了该方法的可靠性。仿真结果表明,在20 Hz~125 Hz范围内,混合FE-SEA方法精度高于统计能量分析(Statistical Energy Analysis,SEA)方法;在125 Hz~400 Hz中频范围内,根据混合FE-SEA方法所得结果与道路试验结果更为吻合,与试验结果的误差最大值不超过3 dB;在400 Hz~1000 Hz范围内,SEA方法的精度逐渐提升,其计算结果与试验值吻合度升高。据此进行的车身部件贡献量分析表明左前侧窗在整个频段内都对驾驶员耳旁噪声有影响,左后侧窗对其贡献量最小。

The windshield noise of a vehicle traveling at high speed was studied.The 1/3 octave sound pressure level and average input excitation at each monitoring point on the vehicle body surface were obtained based on Lattice Boltzmann method(LBM).The FE-SEA hybrid method was used to numerically simulate the vehicle interior aerodynamic noise under the input excitation,the sound pressure level at the driver′s ear was obtained and the reliability of the method was verified by compared the results with the real vehicle road test results.The simulation result shows that the accuracy of the FE-SEA hybrid method is higher than that of the SEA method in the range of 20 Hz-125 Hz;The calculation result of hybrid FESEA model is more consistent with the result of real vehicle road test,and the maximum difference between the test result and the simulation result is less than 3 dB in the medium frequency range of 125 Hz-400 Hz.In the range of 400 Hz-1000 Hz,the accuracy of the SEA method is gradually improved,and the agreement between the calculated results and the experimental values is raised.The analysis of the contribution of vehicle body components shows that the front left side window has some impact on the driver's ear noise in the whole frequency band,and the rear left side window has the least contribution.