侧窗开度连续变化时汽车风振噪声的数值模拟

Numerical Simulation on Vehicle Buffeting Noise with Continuous Change of Side-window Opening

鉴于车辆实际运行中,车窗开启过程是连续的,采用动网格计算方法,对某轿车车型进行连续开启侧窗的风振噪声数值模拟。采用弹簧光顺模型与局部重划模型组合方法实现动网格瞬态仿真,并与传统的固定开度方法和实车道路试验进行对比,验证了该模型与方法的正确性。根据实车道路试验,分析了在不同车速下,驾驶员耳旁风振噪声声压级和频率随侧窗开度变化的规律。根据数值仿真结果,对汽车左后侧窗的最大风振噪声工况的气流性状进行了分析。结果表明,B柱涡的脱落和后视镜产生的尾涡对风振噪声有很大的影响,车厢内部产生的气流分离与涡流导致噪声增大。

In view of that the opening of side-window changes continuously in real vehicle driving condition ,the technique of moving mesh is adopted to conduct a simulation on the buffeting noise of side window with continuous opening in a passenger car. The transient simulation of moving mesh is realized with the combination of spring smoothing model and remeshing model, and the results are compared with that of traditional fixed window o-pening scheme and vehicle road tests,validating the correctness of the models and method adopted. According to the results of real vehicle road tests,the laws of variations of the sound pressure level and frequency of buffeting noise at driver’s ear with the changes of side window opening are analyzed at different vehicle speeds. And based on the results of simulation,the behavior of air flow at left rear side-window in the condition of peak buffeting noise is analyzed with a result showing that the vortex shedding at B-pillar and the vortex wake of rearview mirror have significant effects on buffeting noise and the air-flow separation and vortex occurred in car compartment lead to noise increase.