Characterization of pressure fluctuations within a controlled-diffusion blade boundary layer using the equilibrium wall-modelled LES
Characterization of pressure fluctuations within a controlled-diffusion blade boundary layer using the equilibrium wall-modelled LES
复制标题
使用平衡壁模拟 LES 表征受控扩散叶片边界层内的压力脉动
作者：
R. Boukharfane;M. Parsani;J. Bodart
本文研究了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。这项工作的主要目的是：(I)应用壁面模型大涡模拟(WMLES)方法来预测空气通过受控扩散叶片的流动，以及(Ii)研究湍流边界层与升力面后缘相互作用产生的叶片宽带噪声。本研究是针对马赫数的两个值$${{
M Ma}}_{Infty}=0.3$$Ma∞=0.3和0.5，弦雷诺数的两个值，$${{
M Re}=8.30imes 10^5$$Re=8.30×105和$2.29imes 10^6$2.29×106，两个攻角，AOA$$=4∘和$$5^CIRC$$5∘。为了考察网格分辨率对气动和气声量的影响，我们将我们的结果与文献中提供的实验数据进行了比较。我们还将我们的结果与由两个壁分辨大涡模拟(WRLES)计算生成的两个内部数值解进行了比较，其中一个计算具有类似于DNS的分辨率。结果表明，WMLES能准确地预测平均压力系数分布、速度统计(包括平均速度)和雷诺张量分量的轨迹。此外，我们观察到WMLES计算的瞬时流动结构与参考WMLES数据库中发现的相似，但在前缘区域附近除外。在这些结构中观察到的一些差异与前缘附近的跳跃和向湍流机制的转变有关，这些机制受到网格分辨率的显著影响。气动噪声计算表明，用WMLES得到的功率谱密度分布与实验数据吻合较好。
In this study, the generation of airfoil trailing edge broadband noise that arises from the interaction of turbulent boundary layer with the airfoil trailing edge is investigated. The primary objectives of this work are: (i) to apply a wall-modelled large-eddy simulation (WMLES) approach to predict the flow of air passing a controlled-diffusion blade, and (ii) to study the blade broadband noise that is generated from the interaction of a turbulent boundary layer with a lifting surface trailing edge. This study is carried out for two values of the Mach number, $${{
m Ma}}_{infty } = 0.3$$ Ma ∞ = 0.3 and 0.5, two values of the chord Reynolds number, $${{
m Re}}=8.30 imes 10^5$$ Re = 8.30 × 10 5 and $$2.29 imes 10^6$$ 2.29 × 10 6 , and two angles of attack, AoA $$=4^circ$$ = 4 ∘ and $$5^circ$$ 5 ∘ . 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.