Gaining insights into flame behaviour at small scales can lead to improvements in the efficiency of micro-reactors, compact power generation systems, fire safety technologies, and various other applications where combustion is confined to micro or mesoscales. Flame regimes observed in mesoscale combustors, namely Stable flame, Flames with repetitive extinction and ignition, and Propagating flame, exhibit unique dynamic characteristics that differentiate them from one another. In this study, we systematically examine the various flame regimes observed in mesoscale combustors from both dynamical and statistical standpoints. Our experimental methodology involves stabilizing a flame inside a quartz tube (an optically accessible mesoscale combustor) with an inner diameter of 5 mm. A premixed methane-air mixture is used as fuel, with its equivalence ratio and Reynolds number being the input parameters. Instantaneous OH* chemiluminescence and Acoustic pressure signals, along with high-speed flame imaging, were acquired for combustion dynamics characterization. The objective of this study is to analyze the distinct dynamical signatures associated with these observed flame regimes. For this purpose, Recurrence Quantification Analysis, followed by a Statistical-Spectral analysis, has been performed based on the experimentally acquired OH* Chemiluminescence and Acoustic pressure time-series signals. Subsequently, a stacking ensemble-based machine learning framework has been implemented for mesoscale flame regime classification based on the features extracted from the two aforementioned analyses. In addition, Continuous wavelet transform (CWT) scalograms and three-dimensional phase plots have been graphed to visually elucidate the evolution of system dynamics and the complex interaction of competing time scales in these flame regimes.
Coupled interaction between acoustics and unsteady flame dynamics during the transition to thermoacoustic instability in a multi-element rocket combustor
On the spatial structure and intermittency of soot in a lab-scale gas turbine combustor: Insights from large-eddy simulations
Barcelona Supercomputing Center（巴塞罗那超级计算中心）；Eindhoven University of Technology（埃因霍温理工大学）；Eindhoven Institute for Renewable Energy Systems（埃因霍温可再生能源系统研究所）
Spectral effects of radiating gases on the ignition in a multiswirl staged model combustor using full-spectrum k distribution method -- A Large Eddy Simulation Investigation
Coupled thermoacoustic resolvent analysis of a model two-stream coaxial combustor
State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences（中国科学院力学研究所非线性力学国家重点实验室）；Department of Mechanical Engineering, National University of Singapore（新加坡国立大学机械工程系）；School of Engineering Sciences, University of Chinese Academy of Sciences（中国科学院大学工程科学学院）
Nonlinear responses of the premixed V-flame subjected to dual-frequency disturbances
Beihang University（北京航空航天大学）；Beijing Institute of Control Engineering（北京控制工程研究所）；Imperial College London（伦敦帝国学院）；Research Institute of Aero-Engine, Beihang University（北京航空航天大学航空发动机研究院）；Hangzhou International Innovation Institute, Beihang University（北京航空航天大学杭州国际创新院）
