CAJ | 학술논문

为了探讨亚声速射流气动声场中的主要噪声源以及声波产生机理，基于大涡模拟方法与高精度加权本质无振荡混合格式，对亚声速脉冲射流初始流场的发展过程进行了数值模拟，并根据得到的动力学流场对气动声场进行了直接计算。数值结果描述了射流剪切层在Kelvin-Helmholtz不稳定作用下失稳卷起小涡序列以及相邻小涡间相互旋转合并现象，并发现脉冲射流场的主要声源包括由前导压缩波形成的脉动噪声源、涡合并形成的四极子声源以及涡核内因涡卷起、变形与破碎所形成的湍流混合噪声源。其中，脉动噪声源最强，而涡合并所产生的四极子声源在整个声场中占主导地位。
위료탐토아성속사류기동성장중적주요조성원이급성파산생궤리，기우대와모의방법여고정도가권본질무진탕혼합격식，대아성속맥충사류초시류장적발전과정진행료수치모의，병근거득도적동역학류장대기동성장진행료직접계산。수치결과묘술료사류전절층재Kelvin-Helmholtz불은정작용하실은권기소와서렬이급상린소와간상호선전합병현상，병발현맥충사류장적주요성원포괄유전도압축파형성적맥동조성원、와합병형성적사겁자성원이급와핵내인와권기、변형여파쇄소형성적단류혼합조성원。기중，맥동조성원최강，이와합병소산생적사겁자성원재정개성장중점주도지위。
To discuss the main sources of aeroacoustic field and generation mechanism of acoustic waves,the process of initial flow field development in a subsonic pulse jet is simulated by using the large-eddy simulation and the high-order hybrid-weight essentially non-oscillatory scheme, and the corresponding aeroacoustic field is calculated directly based on the obtained dynamics flow. The numerical results reveal the phenomena of the vortexlets rolled up due to the Kelvin-Helmholtz instability of jet shear layer and the pairing process of neighbor vortices. Calculation results also reveal that the main acoustic sources of the pulse jet include the pulse acoustic source generated by precursor compressible waves, the quadrupole source generated by the vortex pairing and the turbulent blend acoustic sources caused by rolling up,deforming and breakup of the vortexlets within the main vortex ring. The pulse acoustic source is the strongest and the quadrupole source dominates the whole acoustic field.