Spinning front formation in fuel gas-air flame

The method of forming a spinning front of the flame in a propane-air mixture in a flat gap between two plates is proposed. It is shown that the spinning flame fronts (SFFs) are formed in gas mixtures with an excess fuel component and are due to the decay of an initial cylindrical front. It is established that the decay of a cylindrical front is related to the onset of a thermodiffusion instability, which is accompanied by the suppression of the majority of small perturbations on the flame surface and results in the development of only two of these perturbations. The subsequent evolution of the fields of temperatures, concentrations, and velocities in the vicinity of the leader points of developing perturbations results in the formation of an SFF, which resembles extended arc-shaped whiskers. Temporal variations in the angular and tangential velocities of SFF propagation are determined.