Matched hybrid approaches to predict jet noise by using Large-Eddy Simulation
Matched hybrid approaches to predict jet noise by using Large-Eddy Simulation
复制标题
使用大涡模拟预测喷气噪声的匹配混合方法
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
C. Bailly
中科院分区：
文献类型：
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作者：
Guillaume Bodard;C. Bailly
发展了一种结合大涡模拟和湍流噪声源统计模拟的混合声学方法来预测真实射流的噪声。主要目标是融合两种预测模型的优点，以获得稳健的工业声学工具。因此，经典的Ffowcs-Williams&Hawking波外推方法被用来获得谱的低频部分。利用和奥里奥特的细尺度湍流噪声理论对重构的平均流场进行了高频部分的估计。本文报道了这种混合喷流噪声预报方法以及等温亚声速和加热亚音速喷流(M=0.9)的气动声学结果。在混合层中观察到了对湍流水平的过高估计，导致两种模拟的势核都较短。然而，使用按势核长度归一化的距离，速度分布和湍流长度尺度是令人满意的。因此，即使角度变化和温度影响似乎得到了很好的评估，所获得的噪声水平也被高估了。
An hybrid acoustic method combining a large eddy simulation and a stastistical modelling of turbulent noise sources is developed to predict noise of real jets. The main objective is to merge advantages of both kind of prediction model to obtain a robust industrial acoustic tool. Thus, the Ffowcs-Williams & Hawkings Wave Extrapolation Method is classically used to obtain the low frequency part of spectra. The higher frequency part is estimated by means of Tam & Auriault’s fine-scale turbulence noise theory applied to a reconstructed unfiltered mean flow field. This hybrid jet noise prediction method as well as aeroacoustics results for isothermal and heated subsonic jets (M = 0.9) are reported in this paper. An overestimation of turbulence levels in mixing layers is observed, leading to a shorter potential core for both simulations. However, velocity profiles and turbulence length scales are satisfactory by using normalized distances by the potential core length. Noise levels obtained are consequently overpredicted even if angular variations and temperature effects seem well evaluated.