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在航空声学风洞中进行了摇臂式起落架结构件的气动噪声试验,获取起落架结构件气动噪声的频谱特性曲线,研究了起落架的噪声产生机制和噪声源特性。通过对起落架局部构型的调整,探索降低起落架噪声的方法。结果表明:摇臂式起落架部件辐射的噪声随着来流速度的增加而增大;噪声频谱呈现宽频的特性,频谱中具有明显的优势频率;噪声源具有偶极子声源性质,且具有一定的指向性;噪声频谱中所包含的某种纯音成分为起落架上某些孔洞所致的自激振荡噪声;封堵起落架上的这些孔洞或者减小起落架的长度能降低噪声声压级。
Aeroacoustic wind tunnel was used to test the aerodynamic noise of the rocker arm gear. The spectral characteristics of the aerodynamic noise of the landing gear were obtained. The noise generation mechanism and noise source characteristics of the gear were studied. Through the adjustment of the local configuration of the undercarriage, explore ways to reduce the noise of the undercarriage. The results show that the radiated noise of rocker landing gear components increases with the increase of the flow velocity. The noise spectrum shows the characteristics of wide frequency and the dominant frequency in the spectrum. The noise source has dipole sound source properties and has Some directional components of the noise spectrum include self-oscillating noise caused by certain holes in the landing gear. Closing these holes in the landing gear or reducing the length of the landing gear can reduce the noise sound pressure level.