Aperiodic instability of the front of a crown forest fire

The stability of the three-zone structure of the front of a crown forest fi re, which includes zones of vaporization, pyrolysis, and combustion gaseous products, is analyzed by the method of small perturbations. This model mor e accurately describes the physics of the actual process of propagation of upper forest fires. A characteristic equation is obtained and an analysis o f its roots yields neutral curves for analysis of the monotonic instability of the fire front. It is shown that instability of fire-front propagation arises in a certain wavelength range.