Three-dimensional unsteady solid flame combustion under nonadiabatic conditions

The effect of heat losses on solid flame combustion characteristics is considered. New steady-state three-dimensional periodic regimes are found that do not occur under adiabatic combustion conditions. The essence of these regimes is explained using as an example the regime with six spots moving on helical lines in the near-surface layers of a cylinder. The spots are localized in the near-surface layers of a cylinder and do not intersect the central (located along the axis) zone of the sample. The interior of the cylinder (core) burns in a steady-state regime; i.e., along the cylinder axis, the front propagates at a constant velocity. An explanation is given for the existence of such regimes.