Prediction of combustion noise of an enclosed flame by simultaneous identification of noise source and flame dynamics
Prediction of combustion noise of an enclosed flame by simultaneous identification of noise source and flame dynamics
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DOI：
10.1016/j.proci.2018.05.124
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发表时间：
2019-01-01
影响因子：
3.4
通讯作者：
Polifke, W.
中科院分区：
文献类型：
--
作者：
Merk, M.;Gaudron, R.;Polifke, W.
大涡模拟 (LES) 与先进的系统辨识 (SI) 相结合，可同时推断燃烧噪声源的模型以及对湍流预混火焰速度波动的动态响应。 Box-Jenkins 模型结构允许根据单个 LES 生成的时间序列数据对噪声源和火焰动力学进行 SI 分析。这种“黑匣子”SI 方法产生的模型纯粹是数据驱动的，不依赖于特征流或火焰参数（例如湍流强度或火焰长度）的估计。在密闭燃烧系统中，燃烧噪声的频谱分布受到腔声学和火焰动力学的强烈调制。通过将识别的模型合并到燃烧器声学网络模型中，建立线性降阶模型（ROM）来预测两种不同出口反射条件下燃烧器内声压的频谱分布。所确定的火焰传递函数以及基于 ROM 的燃烧室压力谱预测与测量结果的令人满意的定性和定量一致性进行了比较。基于本征模式分析的压力谱解释阐明了燃烧噪声的产生、火焰动力学和腔体共振之间的相互作用。 (C) 2018 年燃烧研究所。由爱思唯尔公司出版。保留所有权利。
Large-Eddy Simulation (LES) is combined with advanced System Identification (SI) to simultaneously infer models for the source of combustion noise and the dynamic response to velocity fluctuations of a turbulent premixed flame. A Box-Jenkins model structure allows SI of both the noise source and the flame dynamics from time series data generated with single LES. The models that result from this 'black-box' SI approach are purely data-driven and do not rely on estimates of characteristic flow or flame parameters, such as turbulence intensity or flame length. In confined combustion systems the spectral distribution of combustion noise is strongly modulated by the cavity acoustics and the flame dynamics. By incorporating the identified models into a network model for the combustor acoustics, a linear Reduced Order Model (ROM) is built to predict the spectral distribution of sound pressure within the combustor for two different outlet reflection conditions. The identified flame transfer function as well as the ROM-based predictions of the pressure spectra in the combustor are compared with satisfactory qualitative and quantitative agreement against measurements. An interpretation of the pressure spectra based on eigenmode analysis elucidates the interplay between combustion noise generation, flame dynamics and cavity resonances. (C) 2018 The Combustion Institute. Published by Elsevier Inc. All rights reserved.