空腔的非定常可压缩过流及相关气动声学问题

THREE-DIMENSIONAL UNSTEADY COMPRESSIBLE FLOW OVER AN OPEN CAVITY AND RELEVANT AEROACOUSTICS

使用大涡模拟-声学比拟相结合的方法,研究三维开式空腔的非定常可压缩过流及其相关的气动声学问题。近场的声源流场部分使用大涡模拟,声音向远场的辐射使用Ffowcs Williams-Hawkings(FW-H)声学比拟,建立了适合于开式空腔的全三维计算气动声学预测方法。文中突出了声源采样时间和积分模数的选择问题。

Three-dimensional （3D） unsteady compressible flow over an open cavity and the relevant aeroacoustics are studied using a hybrid LES-acoustic analogy method. Large-eddy simulation （LES） is used to compute the acoustic source while the Ffowcs Williams - Hawkings （FW-H） acoustic analogy is employed for prediction of the acoustic far-field. The hybrid method is assessed in an open cavity flow at a Mach number of 0.85 and a Reynolds number of Re=1.36×10^6. The technical issues of the proper selection of integration period and modes of sound sources in the frequency domain have been identified. The developed hybrid method has shown promise to be a feasible, accurate and computationally affordable approach for computational aeroacoustics.