Rijke管自激热声振荡的数值模拟  

Numerical simulation of self-excited thermoacoustic oscillation in Rijke tube

作　　者：初敏[1] 徐旭[1] 

机构地区：[1]北京航空航天大学宇航学院,北京100191

出　　处：《声学学报》2015年第1期82-89,共8页Acta Acustica

摘　　要：为了对热声不稳定的发生及控制机理进行研究,对Rijke管内的自激热声振荡现象进行了数值模拟。采用具有低频散低耗散特点的计算气动声学方法,对带有非线性热源项的声波方程进行数值求解,并比较了不同的热源模型及边界条件对非线性效应的影响。结果表明,计算气动声学方法可以成功捕捉到Rijke管内压力的起振过程,而且在速度扰动达到平均流速度的1/3时,振荡会由线性增长转为非线性增长,最终达到有限幅值极限循环。相比热源项,考虑管口辐射耗散的非线性边界条件在振荡幅值和频谱方面对结果的影响都比较小。数值模拟得到的结果与实验符合较好,表明计算气动声学方法适合于热声振荡问题的研究。Numerical simulation of self-excited thermoacoustic oscillation in a Rijke tube was performed in order to research the mechanism of the excitation and controlling strategy of thermoacoustic instabilities. Acoustic perturbation equations with nonlinear heat source were solved by computational aeroaeoustics, which was less dispersive and dissipa- tive. The influence of different heat sources and boundary conditions to nonlinear effects was researched. The results showed that, the start- oscillation phenomenon and the limited cycle can be obtained by computational aeroacousties. The nonlinear behavior commenced at 1/3 of the mean flow velocity. Compared to the heat source, the influence of the nonlinear boundary was small, especially on the amplitude and spectrum. The numerical results showed good consis- tency with experiment. It turns out that, computational aeroaeoustics is available to the simulation of thermoacoustic oscillation.

关 键 词：热声振荡 数值模拟 RIJKE管 自激 非线性边界条件 非线性效应 声学方法 管内压力 

分 类 号：O422[理学—声学]