轿车后视镜尾部气流脉动压力场分布及向车室内传递气流噪声的理论估算

Study on the Fluctuation Pressure Field behind the Back Mirror of a Sedan and Its Influence on Interior Noise

本文通过风洞试验研究了桑塔纳轿车后视镜产生的脉动压力场的分布情况。发现其脉动压力的能量主要集中在轿车通风窗与前侧窗的外表面位置,且其能量很大,相当于90km/h的车速下,最大处脉动压力级达132.5dB,成为一个大声源,透过玻璃向车内传递气流噪声。最后,根据理论推导证明了传递到车室内的气流噪声功率与脉动压力的平方成正比,并近似估算出在90km/h速度下由桑塔纳后视镜产生的传递到车内的气流噪声功率约为2.51×10~3W。

This paper studied the fluctuation pressure field behind the back mirror of a Santana car by wind tunnel experiments. It was found that most of the energy of fluctuation pressure was concentrated on the outer surfaces of vent window and front side window of the car. The energy was enormous with a highest value of about 132.5 dB at the car speed of 90 km/h. This was a strong sound source transmitting aerodynamic noise into the passenger compartment. Finally, the power of aerodynamic noise was proved theoretically to be proportional to the square of airflow fluctuation pressure and a calculation example for Santana sedan was also given.