飞机发动机短舱声传播预计方法研究

Research on Prediction Method of Noise Acoustic Propagation in a Turbofan Aircraft Engine Nacelle

针对飞机发动机短舱的声传播预计方法开展研究。应用有限元方法求解时域线化欧拉方程方程,用Ingard边界条件模拟声衬;特别的,应用流动梯度去除方法抑制发动机排气道噪声预计中产生的Kelvin-Helmholtz不稳定波。针对飞机发动机短舱进气道噪声、排气道噪声在有/无声衬作用下的声传播开展了预测,通过与国际上公开的试验结果进行了对比。结果表明,数值预测噪声指向性与试验基本吻合,误差低于3dB,Kelvin-Helmholtz不稳定波被有效抑制。文章给出的飞机发动机短舱声传播预计方法精度高,结果可信,可用于短舱声传播研究。

This article conducts the research on the prediction method of acoustic propagation in aircraft engine nacelle.The finite element method is was used to solve the time-domain linearized Euler equations,and the Ingard boundary condition iwas used to simulate the acoustic liner;Iin particular,the flow gradient removal method wais used to suppress the Kelvin-Helmholtz unstable wave generated in the noise prediction of the engine exhaust duct.The noise propagation of aircraft engine nacelle inlet noise and exhaust noise under the action of acoustic lining was carried out to predict.The results of comparison with internationally published experimental results show that the directivity of numerical prediction of noise is basically the same as that of the experiments.It is consistent with the experient,the error is less than 3dB,and the Kelvin-Helmholtz unstable wave is effectively suppressed.The prediction method of aircraft engine nacelle acoustic propagation given in the article has high accuracy and credible results,which can be used for research on nacelle acoustic propagation.