某SUV镂空尾翼气动噪声特性的研究

Study on Aerodynamic Noise Characteristics of SUV Hollow Roof Spoiler

在某SUV开发过程中,为了更好地体现运动感,外造型上设计了带镂空的尾翼,然而,镂空尾翼带来了新的气动噪声源,使得车内噪声性能严重恶化。本文通过对风洞测试结果与数值模拟流场的分析,明确了镂空尾翼的声源产生原因:一是气流在镂空通道加速并冲击后风挡产生;二是气流在尾翼尾部区域分离、耦合形成的高湍流强度涡漩辐射产生。基于此,明确了优化方向:减少镂空处的气体流量;降低尾翼下方气流速度;改变尾翼下方气流流动方向。制定了具体的优化方案,并通过了风洞试验验证。结果表明优化方案对提高车内语音清晰度和降低车内声压级都有显著效果,车内声压级降低至少2 dB(A),语音清晰度分别提高0.7%、1.5%、1.7%。通过本文研究内容,可以为尾翼造型设计及优化提供重要依据。

In the development process of an SUV model,in order to highlight the sense of sportive styling,a hollow roof spoiler is designed in the exterior styling.However,the application of the hollow roof spoiler results in a new aero-acoustics noise source,which seriously deteriorates the interior noise performance.Through the analysis of the wind tunnel test results and the numerical simulation,the mechanism of the noise caused by the hollow roof spoiler is identified in this paper.Firstly,the airflow accelerates in the hollow channel and directly hits the windshield,and secondly,the airflow is separated and coupled in the wake of the roof spoiler to form high turbulence intensity vortex radiation.Based on the noise generation principle,this paper proposes a corresponding optimization scheme:reducing the flux of the air flow passing through the channel;reducing the velocity of the air flow passing through the channel;changing the direction of the air flow passing through the channel.The corresponding optimization schemes are formed and verified by the wind tunnel test.The test results show that the optimization scheme has a significant effect on improving the articulation index in the vehicle and reducing the sound pressure level in the vehicle,with the sound pressure level reduced by 2 dBA at least,and the articulation index improved by 0.7%,1.5%,1.7%for each scheme.The research in this paper can provide an important basis for the hollow roof spoiler design and optimization.