飞行器高速气流流经空腔对噪声抑制优化仿真

Simulation and Optimization of Aerodynamic Noise Suppression During High Speed Airflow Blowing Over Cavity

高速气流流经飞行器空腔,会产生强烈的气动噪声,对空腔结构造成很大的威胁。传统噪声抑制方法(如前缘吹气、扰流板、射流等)主要通过改变空腔的流场,达到抑制噪声的且的,但结构复杂,且破坏空腔外部构型,因此需要寻找新的噪声抑制方法。基于可控阻抗边界的噪声抑制方法,无需引入额外装置。采用仿真方法对声阻抗抑制空腔噪声可行性进行了研究,通过对比分析空腔底面不同测点的声压频谱特性,研究了不同壁面声阻抗值对空腔噪声的抑制效果。研究结果表明:利用声阻抗能够有效抑制空腔的前三阶峰值噪声,空腔后缘产生的噪声在向前传播过程中有所衰减,具有良好的工程应用前景。

When a high speed airflow blowing over cavities, intense aerodynamic noise can induce, this may damage its structural components. Conditional noise suppression methods, such as blowing in the leading edge, spoiler and jet flow, mainly control noise by changing cavity＇s flow field, but the device which used is quite complex, and needs to damage cavity＇s formations, so new noise suppression methods should be sought. Cavity noise control method based on impedance needs no additional equipment. For this purpose, a numerical study is conducted to research this suppression method. By analyzing the sound pressure frequency spectrum characteristics at different measurement points, the effect of controllable impedance boundary on cavity＇s sound pressure was studied. The results indicate that the sound pressure level of the third peak frequency noise is suppressed effectively, the noise produced in the rear is attenuated during its radiating process towards upstream, and the control method has some practical value in engineering.