湍流参数对风扇宽频噪声预测影响

Influence of turbulent parameters on fan broadband noise prediction

对于现代先进涡扇发动机,占比越来越大的风扇/压气机宽频噪声成为亟需解决的问题。基于三维风扇声源模型,开展了湍流输入参数对宽频噪声预测影响的研究。结果表明:后传声功率级比前传声功率级普遍高5 dB左右;当湍流参数增大时,也会较大幅度改变前传和后传的声功率级,但对频谱形状影响较小;声功率级随湍流积分尺度增大而减小,随背景湍流速度、中心线湍流速度、湍流宽度增大而增大,其中背景湍流速度对宽频噪声影响最大。发现湍流参数通过作用于上洗速度谱来影响宽频噪声预测结果。

For modern advanced turbofan engines,the increasing broadband noise of fan/compressor has become an urgent problem.Based on the 3 D fan sound source model,the influence of turbulent input parameters on broadband noise prediction was studied.As a result,the back-transmission sound power level was generally about 5 dB higher than the front-transmission sound power level.When the turbulent parameters increased,the front-transmission and the back-transmission sound power level could also change greatly,but had little influence on the spectrum shape;the sound power level decreased with the increase of the turbulence integral scale,and increased with the background turbulence velocity,the centerline turbulence velocity and the turbulence width,of which the background turbulence velocity had the greatest influence on the broadband noise.It was found that the turbulent parameters affected the prediction results of broadband noise by acting on the upwash velocity spectrum.