Study of the influence of flame instability on tulip flame formation

To understand the effect of flame instability on the formation of the tulip flame, this paper modified the multiphenomena combustion model and used the CFD code GASFLOW-MPI system to perform a numerical simulation of premixed stoichiometric hydrogen/air deflagration without considering the influence of flame stretch rate, Darrieus-Landau (DL) instability and thermal-diffusive (TD) instability based on the consideration of the heat transfer mechanism. The influence of different control factors on the formation of the tulip flame was compared and analyzed, and the accuracy of the numerical simulation was verified by combining it with experimental results. The research results showed that the coupling effect of DL instability and TD instability was the main reason for the formation of tulip flames, and DL instability played a dominant role. Furthermore, the DL instability determined the growth rate of the deflagration pressure amplitude and its fluctuation frequency. Finally, DL instability and TD instability had a more significant effect on flame propagation than heat loss. When either effect of DL instability and TD instability was ignored as a factor, the pressure gradient near the flame front decreased sharply and no vortex was generated.