仿生非光滑车外后视镜罩气动减阻降噪机理研究

Mechanism Study of Aerodynamic Drag Reduction and Noise Reduction of Bionic Non-smooth Rear-view Mirror Cover

使用DrivAer汽车模型来研究仿生非光滑车外后视镜罩减阻降噪机理.风洞试验验证了LES(Large Eddy Simulation)和k-ε仿真模型的有效性,说明车外后视镜会导致空气阻力和空气噪声增加.在DrivAer汽车模型外后视镜罩造型表面应用仿生非光滑结构,仿真结果表明:车外后视镜上应用仿生非光滑结构,使整车阻力降低5.9%,侧窗外响度降低19.4%;仿生非光滑结构通过改变边界层流动状态,促使涡垫效应形成,减少来流能量损失,提高流场稳定性,进而对整车气动阻力和噪声产生积极的影响.

Using DrivAer vehicle model,the mechanism of drag reduction and noise reduction of bionic non-smooth rear-view mirror cover is studied.Wind tunnel experiments verify the validity of LES(large eddy simulation)and k-εsimulation models,and show that the rear-view mirror can increase air resistance and noise.The bionic non-smooth structure is applied to the surface of rear-view mirror cover of the DrivAer vehicle model.The simulation results show that the reasonable application of bionic non-smooth structure can reduce the resistance of the vehicle by 5.9%and the loudness outside the side window by 19.4%;The bionic non-smooth structure promotes the formation of the vortex pad effect by changing the flow state of boundary layer,which reduces the energy loss of incoming flow,improves the stability of flow field,and then has a positive impact on the aerodynamic drag and noise of the vehicle.