Numerical modeling of self-excited thermoacoustic instability in Rijke tlibe

In order to probe into the mechanism of the excitation and controlling strategy of thermoacoustic instability in the process of combustion, computational fluid dynamics (CFD) was employed to model the self-excited thermoacoustic instability in a Rijke tube combustor. The start-oscillation phenomenon and the limited cycle of the pressure, axis velocity, temperature and the gas density were obtained. The Rayleigh criterion as the key cause of the maintenance of self-excited thermoacoustic instability in Rijke tube combustor was verified using the phase analysis between the pressure and the axis velocity. The oscillating flow field and the temperature field were presented, which visualized the process of thermoacoustic instability. Contrasting to the previous experimental study, the numerical results agreed well with the experimental data, showing that the CFD method is a strong tool to study the self-excited thermoacoustic instability in Rijke tube combustor.