Numerical investigation and experimental test on aerodynamic noises of the bionic rear view mirror in vehicles

At present, there are some researches focusing on optimization of aerodynamic noises on rear view mirrors, but researches on bionic noise reduction of rear view mirrors are rarely reported. Therefore, with an original rear view mirror as the basic model, the paper applied a head convex hull of a dung beetle to the original rear view mirror cover to obtain a bionic rear view mirror, then conducted numerical computation for aerodynamic noises of the bionic rear view mirror and compared the computational results with the original model. Finally, in order to verify correctness of computational results of aerodynamic noises of the rear view mirror, wind tunnel test was conducted on the rear view mirror. Experimental and numerical simulation results were highly consistent in the whole frequency band, so the wind tunnel test could be replaced by numerical simulation. Only one obvious vortex was behind the bionic rear view mirror, but two obvious vortexes with the opposite rotation directions were behind the original rear view mirror. The bionic rear view mirror did not present vortexes near the lateral window, so impacts of vortexes on noises in the vehicle could be eliminated effectively. Pressure difference in front of and behind the bionic view mirror was smaller than the pressure difference in front of and behind the original rear view mirror. Pressure resistance caused by the convex structure outside the rear view mirror was reduced, so noise reduction could be promoted. The convex structure mainly affected the aerodynamic noise in mid-high frequency regions. Compared with the original rear view mirror, noise reduction effects of the bionic rear view mirror were obvious, where the noise reduction amplitude reached 10dB. Noise source size and intensity of the bionic rear view mirror were reduced obviously.

[1]  Lennart Löfdahl,et al.  Comparative Studies between CFD and Wind Tunnel Measurements of Cooling Performance and External Aerodynamics for a Heavy Truck , 2014 .

[2]  Shuguang Zuo,et al.  Study on the aerodynamic noise of internal flow of regenerative flow compressors for a fuel-cell car , 2014 .

[3]  Kenneth J. Christensen,et al.  Special Issue: Green Communications , 2015, Comput. Networks.

[4]  Jinsong Wu,et al.  Design of isotropic orthogonal transform algorithm-based multicarrier systems with blind channel estimation , 2012, IET Commun..

[5]  Chengwen Xing,et al.  Space-Time Network Coding With Transmit Antenna Selection and Maximal-Ratio Combining , 2015, IEEE Transactions on Wireless Communications.

[6]  Shigeru Ogawa,et al.  Side-View Mirror Vibrations Induced Aerodynamically by Separating Vortices , 2016 .

[7]  Zhigang Yang,et al.  Effects of Installation Environment on Flow around Rear View Mirror , 2017 .

[8]  Jin Hwan Ko,et al.  Effect of chord flexure on aerodynamic performance of a flapping wing , 2010 .

[9]  Yiping Wang,et al.  Prediction and optimization of aerodynamic noise in an automotive air conditioning centrifugal fan , 2013 .

[10]  Hassan Hajabdollahi,et al.  Multi-objective aero acoustic optimization of rear end in a simplified car model by using hybrid Robust Parameter Design, Artificial Neural Networks and Genetic Algorithm methods , 2014 .

[11]  Ke Xu,et al.  Energy Management in Cross-Domain Content Delivery Networks: A Theoretical Perspective , 2014, IEEE Transactions on Network and Service Management.

[12]  James P. Johnson,et al.  Experimental Characterization of the Unsteady Flow Field behind Two Outside Rear-View Mirrors , 2008 .

[13]  J K Shang,et al.  Artificial insect wings of diverse morphology for flapping-wing micro air vehicles , 2009, Bioinspiration & biomimetics.

[14]  Lars Davidson,et al.  A Numerical Investigation of the Flow Past a Generic Side Mirror and its Impact on Sound Generation , 2009 .

[15]  Jinsong Wu,et al.  Survey of Strategies for Switching Off Base Stations in Heterogeneous Networks for Greener 5G Systems , 2016, IEEE Access.

[16]  Hiroshi Tanaka,et al.  A CFD Analysis Method for Prediction of Vehicle Exterior Wind Noise , 2017 .

[17]  Jinsong Wu,et al.  Reliable broadband wireless communication for high speed trains using baseband cloud , 2012, EURASIP J. Wirel. Commun. Netw..

[18]  Jinsong Wu,et al.  Efficient Indoor Fingerprinting Localization Technique Using Regional Propagation Model , 2014, IEICE Trans. Commun..

[19]  Xiaowen Song,et al.  Use of bionic inspired surfaces for aerodynamic drag reduction on motor vehicle body panels , 2011 .

[20]  Onur Yemenici.  Pressure Measurements of the Flow over a Rearview Side Mirror , 2013 .

[21]  James W. Gregory,et al.  Investigation of Side-View Mirror Flow-Induced Vibration Phenomena , 2010 .

[22]  Tharmalingam Ratnarajah,et al.  Iterative Multiuser Detection and Decoding for DS-CDMA System With Space-Time Linear Dispersion , 2009, IEEE Transactions on Vehicular Technology.

[23]  Yao Jianjun.  Numerical simulation of the drag reduction characteristics of a bionic jet surface aperture coupled with jet speed , 2012 .

[24]  Ram Bansal,et al.  CFD Simulation for Flow over Passenger Car Using Tail Plates for Aerodynamic Drag Reduction , 2013 .

[25]  M. Maffei,et al.  Improvements of the Beamforming Technique in Pininfarina Full Scale Wind Tunnel by using a 3D Scanning System , 2008 .

[26]  Yong Oun Han,et al.  Experimental investigation of wake structure around an external rear view mirror of a passenger car , 2011 .

[27]  Jin Yi-feng.  Simulation Study into the Influence of Appearance Variation of a Sport Car's Rear Wing on the Aerodynamic Lift , 2012 .

[28]  Chengwen Xing,et al.  Energy-Efficient Power Control for Device-to-Device Communications , 2016, IEEE Journal on Selected Areas in Communications.