On the stability of combustion and laser‐produced ablation fronts

A correct approach to the problem of a reduction of the growth rate of the Rayleigh–Taylor (RT) instability in an ablation wave is demonstrated in this paper by considering a slow combustion wave in a gravitational field. It is shown that both the supplementary condition required in the model of discontinuity and the reduction of the instability growth rate can be obtained only by solving the complete system of equations, including the equation of thermal conductivity and energy release which are responsible for the wave propagation and the finite thickness of the wave front. The point is that there is no stabilization of the growth rate of RT instability by a mass flow in the limit of zero thickness of the wave front. The reduction of the growth rate can be obtained rigorously for a finite thickness of the wave front only.