Physics-informed modeling of afterburn in explosive simulations with GPU-accelerated CFD

Quasi-static pressure (QSP) in confined detonations is dominated by the internal-energy rise of the enclosed gases and, for oxygen-deficient charges, by post-detonation “afterburn” of detonation products and binder with atmospheric oxygen.

We present a new explicit afterburn model in Viper Blast and compare this to confined detonation experiments for PE10. The newly developed explicit afterburn model in Viper Blast is outlined, and it is shown how the model tracks both the detonation and combustion products through separate species, with the afterburn combustion process both limited by stoichiometry and temperature. This method is compared to the classic Miller-type afterburn process currently available in Viper Blast – and it is shown that it removes user input for both the amount of afterburn energy and time scales for combustion.

Initial results using the new Viper Blast implementation reproduce the experimental PE10 trends in air and nitrogen. We outline the variable gamma methodology used inside the explicit solver without sacrificing GPU performance.