THE INFLUENCE OF CELLULAR STRUCTURE ON DETONATION TRANSMISSION

We present two-dimensional numerical simulations of the transmission o f detonation from a rectangular channel into a larger volume. The simu lations solve the Euler equations on a Cartesian grid using the method of Flux-Corrected Transport for the fluid equations and a two-step in duction parameter model for the chemistry. We simulate detonation in a H-2/O-2/Ar mixture and use sufficient grid resolution to resolve the cellular structure of the detonation. When a planar detonation front w ithout a resolved cellular structure expands into the larger volume, t he reaction front separates from the shock front and the detonation fa ils. When the planar front is perturbed to induce a quasi-regular cell ular structure in the detonation, it again initially begins to fail, b ut now the presence of the transverse waves leads to reignition of the detonation in the larger volume. The form of this reignition shows st riking similarities to the reignition of detonation which has been see n experimentally in H-2/O-2 mixtures. We describe this reignition mech anism in detail, and also investigate the dependence of the reignition on the number of cells in the detonation front.