Wind noise from A-pillar and side view mirror of a realistic generic car model, DriAver

Abstract

Interior noise of a production car is a total contribution mainly from engine, tyres and aerodynamics. At high speed, wind noise can dominate the total interior noise. Wind noise is associated with the unsteadiness of the flow. For most production cars, A-pillar and side view mirror are the regions where the highly separated and turbulent flows are observed. This study quantifies the wind noise contribution from A-pillar and side view mirror with respect to the interior noise of a generic realistic model, DrivAer. The noise sources are obtained numerically from the flow-structure interactions based on the unsteady Reynolds averaged Navier stokes (URANS) while the noise propagation is estimated using Curle's equation of Lighthill acoustic analogy. The sound pressure frequency spectrum of the interior noise is obtained by considering the sound transmission loss from the side glass by using the mass law for transmission loss. The study found that the noise from the A-pillar is higher than the noise from the side view mirror in the whole frequency range. Near the end of the A-pillar component contributes the highest radiated noise level with up to 20 dB louder than that at the front part of the A-pillar. Keywords: DrivAer; A-pillar; side view mirror; wind noise. Reference to this paper should be made as follows: Ali, M.S.M., Jalasabri, J., Sood, A.M., Mansor, S., Shaharuddin, H. and Muhamad, S. (2018) 'Wind noise from A-pillar and side view mirror of a realistic generic car model, DriAver', Int. Jafirdaus Jalasabri is a CAE Engineer at the Proton Sdn. Bhd. He received his Bachelor degree from the Universiti Putra Malaysia (UPM). He has been involved significantly in new developments of many new Proton cars. His research interests include design of experiments and vehicle wind noise. He has expertise in computational fluids dynamics (CFD) using commercial and open source software. Currently, he is writing a code for aeroacoustics performance using Octave GNU. He also published papers related to CFD, including in the aeronautics field. Anwar Mohd Sood received his Master's degree from the Islamic International University Malaysia (IIUM). His Master degree project is on Drag Reductions of Passenger Cars. He is currently the Lead Engineer of CFD Group at Proton Sdn. Bhd. He has also involved significantly in new developments of many new Proton cars. He has a strong passion on aerodynamic issues related to cars. He is expert in computational fluids dynamics, with an experience of more than ten years. 40 M.S.M. Ali et al.