高速汽车侧窗气流噪声模拟

Simulation on Aerodynamic Noise of Automobile's Side Window at High Speed

汽车高速行驶条件下,气流噪声成为了主要的噪声源。在组成气流噪声的三部分中,偶极子源噪声占主导地位,而偶极子源噪声又取决于车身表面脉动压力。利用fluent软件,采用大涡模拟(LES)方法,对汽车模型的表面脉动压力进行数值模拟,计算所得脉动压力值与试验测试值基本吻合。对模型的挡风玻璃、A柱和C柱都进行修改,并对侧窗脉动压力值进行模拟计算。模拟仿真表明,汽车挡风玻璃圆弧化和A柱的圆角化有利于降低侧窗脉动压力值,但是C柱的圆角化并不能够降低侧窗脉动压力值,反而会增加侧窗后半部分的脉动压力值。

Aerodynamic noise will become the main noise source,when automobile runs at high speed.The aerodynamic noise around automobiles is dominated by dipole source which depends on fluctuation pressure around automobiles.The numerical simulation about fluctuation pressure around automobile model is based on FLUENT software by LES method.It is approved that the calculated results of fluctuation pressure can fairly agree with the experimental results.Then simulating on fluctuation pressure around the side window when front window becomes to circle arc,and A-poles and C-poles have round corners.The simulations show that it is useful to reduce fluctuation pressure of side window when automobile have a circle arc front window and round cornered A-poles.But the fluctuation pressure of side window would increase rather than decrease when having round cornered C-poles.