摘要
矩形喷管因其优异的推力矢量控制和隐身性能在军用飞机设计中日益受到重视,而双喷流耦合干扰是一个很有吸引力的气动声学问题,其噪声特征和发声机理仍不十分明确。采用高精度数值格式和隐式大涡模拟方法,对超声速欠膨胀单/双矩形喷流开展数值仿真研究,预测的单喷流流声特性与实验结果吻合较好。研究结果表明,当双喷流间距为3.5h时,双喷流相互作用对喷流内部结构与剪切层发展的影响并不显著,但单/双喷流总声压级分布和声指向特征存在明显差异,与单喷流相比,双喷流啸声频率略微减小,啸声强度有较大幅度提升。采用傅里叶模态分解和谱本征正交分解提取流场相干结构,单喷流中呈现螺旋模态,而双喷流中切换为沿短轴方向的摆动模态,且两喷流摆动相位同步。模态分析进一步指出了啸声频率和强度上的变化与声源位置偏移的关联。
Rectangular nozzles are increasingly valued in military aircraft design due to their excellent thrust vectoring control and stealth performance.However,twin jet coupling remains an attractive aero-acoustic problem as its noise characteristics and sound generation mechanism are still not well understood.In this paper,numerical simulations of supersonic under-expanded single/twin rectangular jets are conducted.High-precision numerical schemes and implicit large eddy simulation methods are used,and the predicted flow and acoustic characteristics of the single jet show good agreement with the experimental results.The findings indicate that when twin jet spacing is 3.5h,the interaction between twin jets has little impact on the internal structure and shear layer development of the jets.There are significant differences in the overall sound pressure level distribution and the noise directivity between single and twin jets.Compared with the single jet,twin jets exhibit a slightly reduced screech frequency,and a significantly increased intensity.Fourier mode decomposition and spectral proper orthogonal decomposition are employed to extract coherent structures in the flow field.A helical mode is revealed in the single jet,while in the twin jets,the mode switches to a flapping mode along the minor axis with the two jets oscillating in phase.Modal analysis further highlights the relationship between changes in screech frequency and intensity and the shift in the sound source location.
作者
查君培
陈保
吴飞
李伟鹏
Junpei ZHA;Bao CHEN;Fei WU;Weipeng LI(School of Aeronautics and Astronautics,Shanghai Jiao Tong University,Shanghai 200240,China;Shenyang Engine Institute,Aero Engine Corporation of China,Shenyang 110015,China)
出处
《航空学报》
北大核心
2025年第14期88-102,共15页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(12372221)。
关键词
矩形喷管
双喷流耦合
气动噪声
谱本征正交分解
大涡模拟
rectangular nozzle
twin-jet coupling
aeroacoustics
spectral proper orthogonal decomposition
large eddy simulation
