超声速理想膨胀喷流噪声的大涡模拟  

Large eddy simulation of ideally expanded supersonic jet noise

作　　者：施方成 高振勋[1] 田雨岩 蒋崇文[1] 王田天 李椿萱[1] SHI Fangcheng;GAO Zhenxun;TIAN Yuyan;JIANG Chongwen;WANG Tiantian;LEE Chun-Hian(School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China;College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191 [2]湖南大学机械与运载工程学院,长沙410082

出　　处：《航空学报》2023年第2期101-119,共19页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(11872094,51905547,52078199)。

摘　　要：为探究亚格子模型和热效应对超声速喷流流场与声场的影响规律,采用LES/FW-H混合算法对超声速理想膨胀喷流开展了数值模拟参数研究。首先,通过对比数值模拟与实验数据详细验证了LES/FW-H混合算法的可靠性,并结合Tam相似谱理论确定了实验与数值模拟中声场出现偏差的原因在于实验中存在宽频激波噪声。之后,讨论了亚格子模型对流场平均量、湍流统计量和噪声特征的影响,数据对比表明动态Smagorinsky模型的模拟结果与隐式亚格子模型的结果一致,且均与已有实验和数值模拟结果相符;而采用常系数Smagorinsky模型将导致流场和声场结果出现明显偏差。最后,通过改变喷流出口总温研究了热效应对超声速理想膨胀喷流流场与声场的影响,研究发现喷流总温升高增大了无量纲的高频流向速度脉动,同时对远场高频噪声具有显著的增强效应。To investigate the influence of the subgrid model and thermal effect on the flowfield and sound field of the supersonic jet,parameter studies are performed by using the LES/FW-H hybrid method.First,the reliability of the LES/FW-H hybrid method is verified through comparison of the numerical simulation and the experimental data.Meanwhile,the noise differences between the simulation and experimental results are studied,and the comparison with Tam’s similarity spectra shows that the differences are resulted from the broadband shock-associated noise.Then,the influences of the subgrid model on the mean flowfield,turbulence statistics,and noise characteristics are discussed.The comparisons indicate that the simulation results of the dynamic Smagorinsky model are consistent with those of the implicit subgrid model,both of which are consistent with the existing experiments and numerical simulations.However,the simulation with the constant Smagorinsky model leads to obvious deviations in the flowfield and the sound field.Finally,the influences of the thermal effect on the flowfield and the sound field of the ideally expanded supersonic jet are studied by changing the total temperature at the nozzle exit.It is found that the total temperature increase intensifies the non-dimensional streamwise velocity fluctuation in the high-frequency range and also enhances the far-field high-frequency noise.

关 键 词：气动声学 可压缩湍流 超声速理想膨胀喷流 喷流噪声 大涡模拟 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程] O358[理学—流体力学]