火箭整流罩外气动噪声环境的大涡模拟研究

Large Eddy Simulation of the Aeroacoustic Environment of a Rocket Fairing

基于五阶加权本质无振荡(WENO)格式构造隐式大涡模拟方法(ILES),对跨声速来流条件下(Ma=0.8)火箭整流罩外噪声环境进行数值模拟。通过与风洞试验结果及国外文献进行对比,ILES方法能够在较粗网格下准确预测壁面湍流脉动特性。跨声速流动在壁面折角处出现分离、再附、激波/边界层干扰现象,均方根脉动压力系数出现峰值,同时该区域噪声能量在全频段都较高,易引起结构抖振效应。最后,根据ILES模拟结果,指出工程常用的外噪声经验公式的不足,并提出改进措施。

The implicit large eddy simulation （ILES） method based on the fifth-order weighted essentially non- oscillatory （WENO） scheme is proposed to resolve the unsteady turbulent flow around the fairing wall at Ma = 0.8. The root-mean-square of the fluctuating pressure coefficient distribution and the power spectral density at several locations are presented to compare with wind tunnel data and reference＇s results, demonstrating this method is promising for engineering application with relatively coarse meshes. When the transonic flow passes the corner, it gets separated and interacted with shock waves, resulting in a server fluctuation-pressure level and lower frequency vibration. In the end, the deficiencies of the empirical formulas are denoted and corresponding improvements are proposed based on the results of ILES.