火焰动力学及其对热声稳定性的影响

Flame dynamics and their effect on thermoacoustic instabilities

火焰动力学特性对燃烧系统热声振荡的准确预测和控制具有重要的意义。该文介绍了作者团队近年来针对不同应用背景下的火焰动力学特性在理论建模和实验验证方面的研究,包括理想非预混射流火焰、钝体预混火焰、值班火焰等组织方式以及多维扰动下的火焰动力学特性。其中:通过Green函数法建立了非预混火焰的分布式火焰传递函数;通过火焰面方程和离散涡模型研究了涡和火焰面的相互作用机理;通过双火焰面模型研究了值班火焰和主火焰之间的相互作用机理;通过非对称火焰模型,研究了火焰对不同方向扰动的响应特征。结果表明,将火焰动力学模型与声学网络模型结合分析,可以得到火焰动力学对燃烧室热声稳定性的影响机制。

The flame dynamics strongly affect the accurate prediction and control of self-excited oscillations in combustion systems. This paper introduces the authors’ research on the theoretical modeling and experimental verification of the flame dynamics characteristics for various practical application backgrounds, including ideal non-premixed jet flames, bluff body premixed flames, main/piloted flames and flames with multi-dimensional disturbances. This review presents a distributed flame transfer function for non-premixed flames developed using the Green’s function method. The interaction mechanism between the vortex and the flame surface was studied using the flame surface equation and the discrete vortex model. The interaction mechanism between the pilot flame and the main flame was studied through modeling. The response characteristics of flames to disturbances in various directions were also studied. The flame dynamics model was combined with an acoustic network model to show that the flame dynamics have different effects on the thermoacoustic modal stability.