below is an abstract taken from a NASA paper describing "vorticity" in flame fronts, referred to in linear analysis. (here and other gun mags). if your interested google non-linear detonation analysis
The interaction of an oblique, overdriven detonation wave with a vorticity disturbance is investigated by a direct two-dimensional numerical simulation using a multi-domain, finite- difference solution of the compressible Euler equations. The results are compared to those of linear theory, which predict that the effect of exothermicity on the interaction is relatively small except possibly near a critical angle where linear theory no longer holds. It is found that the steady-state computational results whenever obtained in this study agree with the results of linear theory. However, for cases with incident angle near the critical angle, moderate disturbance amplitudes, and/or sudden transient encounter with a disturbance, the effects of exothermicity is more pronounced than predicted by linear theory. Finally, it is found that linear theory correctly determines the critical angle.
one study that found good correlation
