Large Eddy Simulation for the Analysis of Jet Noise Suppression Devices
Large Eddy Simulation for the Analysis of Jet Noise Suppression Devices
复制标题
用于分析射流噪声抑制装置的大涡模拟
DOI：
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发表时间：
2007
期刊：
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通讯作者：
Markus Olander Burak
中科院分区：
文献类型：
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作者：
Markus Olander Burak
商用飞机的更严格的噪声法规增加了航空航天工业中对降噪技术的兴趣。为了满足这些要求，必须研究新的噪声抑制技术，并且需要验证并可能改进数值方法以正确评估这些新技术。
本论文主要研究含声衬的引射-混合喷管结构的流场和远场声学特性。流场预测采用大涡模拟和基尔霍夫的表面积分技术用于预测的远场噪声。本文采用时域宽带阻抗边界条件公式对Helmholts型声衬进行了建模。在研究的所有情况下，喷嘴几何形状包括在计算域中。
对于混合器-引射器喷管结构，流场被很好地捕捉，并获得了目标质量流量，表明预测是成功的。对于声学衬里模型，实施已被证明是鲁棒的和成本效益。在对实验基准测试用例的验证中，该模型在停滞条件和掠流的情况下都给出了非常好的一致性。
Stricter noise regulations for commercial aircraft have increased interest in noise reduction techniques within the aerospace industry. To meet the requirements new noise suppression technologies have to be delveoped and the numerical methods need to be validated and possibly improved for the correct assessment of these new technologies.
This thesis deals with numerical predictions of flow and far-field acoustic signature for mixer-ejector nozzle configurations including acoustic liners. The flow field predictions are obtained using large eddy simulation and Kirchhoff's surface integration technique is used for predicting the far-field noise. A time-domain broadband impedance boundary condition formulation is used for modeling a Helmholts type acoustic liner. In all cases studied, the nozzle geometry is included in the calculation domain.
For the mixer-ejector nozzle configuration the flow field is well captured and the target mass flows were obtained indicating that the prediction was successful. For the acoustic liner model the implementation has proven to be robust and cost effective. In validations against experimental benchmark test cases the model has given very good agreement in cases with both stagnant conditions and grazing flow.