Experimental analysis of hydrodynamic and acoustic pressure on automotive front side window

Abstract

Both the hydrodynamic and acoustic pressure on automotive front side window have the potential contribution to the interior sound pressure of the vehicle. The corrected force analysis technique (CFAT) is employed to extract the acoustic pressure on front side window. The sensitivity of all pressure fluctuation inside and outside the vehicle to the variation of wind speed, yaw angle and the geometry of side mirror is analyzed. The scaling law of both hydrodynamic and acoustic pressure is derived, compared and used to confirm the validation of CFAT. The coherence function and contribution coefficient are used to analyze the relative contribution of hydrodynamic and acoustic pressure on front side window to the interior sound pressure. Results show that in the middle and high frequency range, although the magnitude of acoustic pressure on front side window is much smaller than that of hydrodynamic pressure, the acoustic pressure on front side window contributes much more than the hydrodynamic pressure into the interior sound pressure.