Rapid noise prediction models for serrated leading and trailing edges
Rapid noise prediction models for serrated leading and trailing edges
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锯齿状前缘和后缘的快速噪声预测模型
DOI：
10.1016/j.jsv.2019.115136
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发表时间：
2019
影响因子：
4.7
通讯作者：
Lorna J. Ayton
中科院分区：
文献类型：
--
作者：
B. Lyu;Lorna J. Ayton
前缘和后缘锯齿已被广泛用于降低诸如对转风扇和大型风力涡轮机等应用中的前缘和后缘噪声。最近的研究表明，这两个噪声问题可以建模分析使用维纳-霍普夫方法。然而，由此产生的模型涉及无限区间积分，不能进行分析评估，因此实施它们带来了实际困难。本文针对锯齿形前缘和后缘平板分别建立了易于实现的噪声预测模型。通过利用高阶模式被截止并且相邻模式在远场中不干涉的事实，除非在足够高的频率下，涉及两个无穷和的无限区间积分近似为单个简单的和。数值比较表明，所得到的模型作为良好的近似原始模型。当前缘模型预测与各种根尖振幅的实验结果进行比较时，也取得了很好的一致性，而TE噪声模型的定性评价表明，湍流边界层下的壁面压力统计的准确表征对于准确的TE噪声预测至关重要。重要的是，本文中开发的模型可以以非常有效的方式进行鲁棒性评估。例如，在标准台式计算机上，典型的远场噪声频谱可以在毫秒内计算出后缘和前缘噪声模型。由于它们的效率和易于数值实现，这些模型预计将是特别重要的应用程序中的数值优化是可能需要的。
Leading- and trailing-edge serrations have been widely used to reduce the leading- and trailing-edge noise in applications such as contra-rotating fans and large wind turbines. Recent studies show that these two noise problems can be modelled analytically using the Wiener-Hopf method. However, the resulting models involve infinite-interval integrals that cannot be evaluated analytically, and consequently implementing them poses practical difficulty. This paper develops easily-implementable noise prediction models for flat plates with serrated leading and trailing edges, respectively. By exploiting the fact that high-order modes are cut-off and adjacent modes do not interfere in the far field except at sufficiently high frequencies, an infinite-interval integral involving two infinite sums is approximated by a single straightforward sum. Numerical comparison shows that the resulting models serve as excellent approximations to the original models. Good agreement is also achieved when the leading-edge model predictions are compared with experimental results for sawtooth serrations of various root-to-tip amplitudes, whereas a qualitative evaluation of TE noise model shows that an accurate characterization of the wall pressure statistics beneath turbulent boundary layers is crucial for an accurate TE noise prediction. Importantly, the models developed in this paper can be evaluated robustly in a very efficient manner. For example, a typical far-field noise spectrum can be calculated within milliseconds for both the trailing- and leading-edge noise models on a standard desktop computer. Due to their efficiency and ease of numerical implementation, these models are expected to be of particular importance in applications where a numerical optimization is likely to be needed.
影响因子：
3.7
作者：
Lorna J. Ayton
通讯作者：
Lorna J. Ayton
影响因子：
3.7
作者：
L. E. Jones;R. Sandberg
通讯作者：
L. E. Jones;R. Sandberg
影响因子：
4.7
作者：
Lau, Alex S. H.;Haeri, Sina;Kim, Jae Wook
通讯作者：
Kim, Jae Wook