Numerical investigation of combustion noise: The Entropy Wave Generator
Numerical investigation of combustion noise: The Entropy Wave Generator
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燃烧噪声的数值研究：熵波发生器
DOI：
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发表时间：
2016
期刊：
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通讯作者：
T. Poinsot
中科院分区：
文献类型：
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作者：
C. Becerril;S. Moreau;M. Bauerheim;L. Gicquel;T. Poinsot
本文介绍了EWG亚音速工作点的大涡模拟（Bake等人[9]的第二个试验情况）。这项研究有三个目标。首先是提供一个比RANS模拟和分析模型提供的数据库更大的间接噪声生成数据库。第二是确定亚音速情况下的主要噪声（直接或间接）。三是了解喷管马赫数增大时压力峰值噪声高估的原因（即图1）。作为对第三种现象的解释，Howe [20]首先提出，在喷嘴扩散器中存在气流分离的情况下，涡流声与熵噪声密切相关，并可显著降低总体声级。其次，喷管喉部热段塞的强烈变形降低了段塞前后界面的熵梯度，从而降低了声压。
A Large Eddy Simulation of a subsonic operating point (test case number two from Bake et al. [9]) of the EWG is presented in this paper. This study has three goals. The first is to provide a larger database on the generation of indirect noise than the one provided by RANS simulations and analytical models. The second is to determine the dominant noise in the subsonic case (direct or indirect). The third is to understand the reason of the overestimation of the pressure peak noise when the nozzle Mach number increases (i.e. Figure 1). As an explanation to the third phenomenon, Howe [20] suggested firstly that in cases with flow separation in the nozzle diffuser, vortex sound is strongly correlated with entropy noise and can dramatically reduce the overall sound level. Secondly, the strong deformation of the hot slug in the nozzle throat reduces the entropy gradients within the front and rear interfaces of the slug generating a decrease in acoustic pressure.