Abstract
Flame instability has been observed in many combustion systems such as jet engine, gas turbine combustors and piston ICE. These instabilities are not desirable as it can reduce efficiency and increase pollution. To understand the phenomenon, an experimental study of acoustically excited propane jet diffusion flame under confinement of optically vertical tube, and the jet diffusion flame is positioned along the central axis of the cylindrical tube. Dynamic frequency of a flame plays an important role in flame structure and could indicate flame instability. Therefore, it is important to measure the dynamic of a flame in order to understand the fundamental aspects of combustion process. This paper presents a technique for flame monitoring. The technique is based on using light cell. The experimental results show that this technique can be used for studying the flame dynamics. The power spectrum of signals of the flame has been calculated. It has been demonstrated that optical digital acquisition processing by using light cell technique is a powerful in the investigation, and makes available very detailed power spectra of the flame light emission signals. Moreover, auto-correlation of signals have been presented and analyzed. This study has provided valuable physical insights into the complex combustion dynamics of flames.