Nonlinear Dynamic Characteristics of Turbulent Non-Premixed Acoustically Perturbed Swirling Flames  

作　　者：ZHOU Hao TAO Chengfei MENG Sheng CEN Kefa 

机构地区：[1]State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou,310027,China

出　　处：《Journal of Thermal Science》2022年第3期882-894,共13页热科学学报（英文版）

基　　金：supported by National Science Fund for Distinguished Young Scholars(51825605)。

摘　　要：The main objective of this article was to experimentally investigate the dynamic response of diffusion flame under acoustic excitation in a laboratory-scale burner.Two parametric variations of the burner,the burner inlet length and variation of the airflow rate,were studied.Experimental results were analyzed through nonlinear time series analysis and several resonance characteristics were obtained.Results indicate that the flame-acoustic resonance only appears under certain frequencies together with the fuel tube vibration.Resonance characteristics of the combustion chamber and air inlet in the non-premixed burner indicate quasi-periodic or limit cycle oscillations,respectively.Flame-acoustic resonance would trigger the frequency and amplitude mode-transition in burners.Moreover,the intermittency of flame heat release was observed under variation of inlet length and airflow rate in the burner;the 445 mm case shows more frequency peaks and fluctuations than the 245 mm one.Four typical flame forms were examined during the flame-acoustic resonance conditions,evolves from wrinkled flames to diverged flames,then evolves to reattached flames and finally to blow-off flames.This study proposed the practical application of nonlinear time-series analysis method as a detection tool for flame-acoustic resonance in laboratory non-premixed burners,which could contribute to the detection and prevention of potential thermoacoustic instabilities or resonance structure failures of industrial boilers.Finally,this study demonstrates an alternative to conventional linear tool for the characterization of nonlinear acoustic resonance in industrial boilers.

关 键 词：flame-acoustic resonance non-linear time series analysis non-premixed burners intermittency dynamic characteristics 

分 类 号：TM621[电气工程—电力系统及自动化]