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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。
High-speed airflow through the aircraft cavity, will have a strong aerodynamic noise, the cavity structure poses a great threat. Traditional noise suppression methods (such as leading edge blowing, spoiler, jet, etc.) mainly reduce the cavity flow field to achieve noise suppression, but the structure is complicated and the cavity external structure is destroyed. Therefore, it is necessary to find new Noise suppression method. Noise suppression based on controlled impedance boundaries eliminates the need for additional devices. The feasibility of acoustic impedance suppression of cavity noise was studied by simulation method. By comparing the sound pressure spectrum characteristics of different measurement points on the bottom of cavity, the effect of different wall acoustic impedance on cavity noise suppression was studied. The results show that the use of acoustic impedance can effectively suppress the first three peaks of the cavity noise, and the noise generated at the trailing edge of the cavity attenuates during the forward propagation. Therefore, it has a good engineering application prospect.