We study front solutions of a system that models combustion in highly
hydraulically resistant porous media. The spectral stability of the fronts is
tackled by a combination of energy estimates and numerical Evans function
computations. Our results suggest that there is a parameter regime for which
there are no unstable eigenvalues. We use recent works about partially
parabolic systems to prove that in the absence of unstable eigenvalues the
fronts are convectively stable.Comment: 21 pages, 4 figure