Boukharfane Radouan, Parsani Matteo, Bodart Julien
Computer Electrical and Mathematical Science and Engineering Division (CEMSE), Extreme Computing Research Center (ECRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
ISAE-Supaero, BP 54032, 31055, Toulouse Cedex 04, France.
Sci Rep. 2020 Jul 29;10(1):12735. doi: 10.1038/s41598-020-69671-y.
In this study, the generation of airfoil trailing edge broadband noise that arises from the interaction of turbulent boundary layer with the airfoil trailing edge is investigated. The primary objectives of this work are: (i) to apply a wall-modelled large-eddy simulation (WMLES) approach to predict the flow of air passing a controlled-diffusion blade, and (ii) to study the blade broadband noise that is generated from the interaction of a turbulent boundary layer with a lifting surface trailing edge. This study is carried out for two values of the Mach number, [Formula: see text] and 0.5, two values of the chord Reynolds number, [Formula: see text] and [Formula: see text], and two angles of attack, AoA [Formula: see text] and [Formula: see text]. To examine the influence of the grid resolution on aerodynamic and aeroacoustic quantities, we compare our results with experimental data available in the literature. We also compare our results with two in-house numerical solutions generated from two wall-resolved LES (WRLES) calculations, one of which has a DNS-like resolution. We show that WMLES accurately predicts the mean pressure coefficient distribution, velocity statistics (including the mean velocity), and the traces of Reynolds tensor components. Furthermore, we observe that the instantaneous flow structures computed by the WMLES resemble those found in the reference WMLES database, except near the leading edge region. Some of the differences observed in these structures are associated with tripping and the transition to a turbulence mechanism near the leading edge, which are significantly affected by the grid resolution. The aeroacoustic noise calculations indicate that the power spectral density profiles obtained using the WMLES compare well with the experimental data.
在本研究中，对由湍流边界层与翼型后缘相互作用产生的翼型后缘宽带噪声进行了研究。这项工作的主要目标是：（i）应用壁面建模大涡模拟（WMLES）方法来预测通过可控扩散叶片的气流，以及（ii）研究由湍流边界层与升力面后缘相互作用产生的叶片宽带噪声。本研究针对马赫数的两个值，[公式：见原文]和0.5，弦雷诺数的两个值，[公式：见原文]和[公式：见原文]，以及两个攻角，攻角AoA [公式：见原文]和[公式：见原文]进行。为了研究网格分辨率对气动和气动声学量的影响，我们将我们的结果与文献中可用的实验数据进行了比较。我们还将我们的结果与从两次壁面解析大涡模拟（WRLES）计算生成的两个内部数值解进行了比较，其中一次计算具有类似直接数值模拟（DNS）的分辨率。我们表明，WMLES准确地预测了平均压力系数分布、速度统计量（包括平均速度）以及雷诺张量分量的迹线。此外，我们观察到，由WMLES计算得到的瞬时流动结构与参考WMLES数据库中的结构相似，但在前缘区域附近除外。在这些结构中观察到的一些差异与前缘附近的触发以及向湍流机制的转变有关，这些受网格分辨率的影响很大。气动声学噪声计算表明，使用WMLES获得的功率谱密度剖面与实验数据比较吻合。
