Adaptive mesh refinement based numerical simulation of detonation initiation in supersonic combustible mixtures using a hot jet

Abstract

The open-source program AMROC, implementing a block-structured adaptive mesh refinement method, was adopted for the fine structure numerical simulation of detonation initiation in supersonic combustible mixtures. Simulations were conducted on a nested parallel LINUX compute system. The initiation process was specified as three stages and their respective flow field characteristics were analyzed. Results indicate that a hot jet under specific conditions can have a similar effect as a pneumatic oblique bevel for inducing periodical shock-induced detonative combustion by a bow shock. The interaction of bow-shock-induced combustion with the local detonation wave, produced by the reflection shock on the upper wall, can create a structure with two triple-wave points. The hot jet not only plays a role in the detonation initiation, but also is found to act as a stabilizing control mechanism for detonation propagation. In our simulations, the detonation wave propagates in an overdriven state initially and achieves self-sustaining motion after the shutdown of the hot jet. Subsequently, the final pisiform structure of typical stable Chapman-Jouguet detonation cells is formed.