Structure and stability of premixed flames propagating in narrow channels of circular cross-section: Non-axisymmetric, pulsating and rotating flames

Finally, the stability results are compared successfully with three-dimensional unsteady numerical simulations. They show that for Le < 1 non-axisymmetric flames propagating with a constant velocity appear for positive values of the flow rate. For flames with Le > 1, depending on the channel width, pulsating axisymmetric and rotating non-axisymmetric flames arise. It is demonstrated that when the non-axisymmetric oscillatory perturbations are the most unstable, the flame adopts a multi-headed non-axisymmetric shape and can propagate in a rotating manner while the central part of the flame advances at a constant velocity.