A simplified burn model for simulating explosive effects and afterburning

Abstract

A simplified burn model (SBM) was developed for use in simulating the effects of explosive detonations. The goal of SBM is to provide a subgrid model for detonation propagation on grids that are many times coarser than the physical width of the reaction zone. Similar to traditional programmed burn (PB), SBM provides accurate enough initial conditions for simulating largescale blasts and afterburning processes resulting from the detonation. The governing equations are based on the five-equation compressible multiphase flow model that describes reaction and post-detonation processes similar to reactive burn models. The model uses highly simplified reactant equations of state and reaction rate laws. The reaction model is based on burning rates from traditional PB approaches and is designed to spread the reaction zone over a small number of grid points regardless of the mesh resolution. The detonation velocity and state are independent of the input parameters for the reactant equation of state and reaction model, provided the inputs are physically realistic. The single input parameter for the equation of state must be selected such that the reactant and product Hugoniot curves do not cross, otherwise unphysical weak detonations result. Numerical experiments show that the velocity, state, and bulk structure of Chapman-Jouguet detonations can be reproduced by the model. The resulting blast profiles, pressure-time traces, and detonation velocity for multidimensional simulations are relatively independent on the input parameters, again, provided the inputs are physically reasonable. The simplified burn model shows great potential for simulating afterburning processes with detailed reaction models or explosive particle dispersal. The SBM is relatively straightforward to implement in compressible multiphase flow codes.

Experimental and computational investigation into the hydrodynamics and chemical dynamics of laser ablation aluminum plasmas

“…56 Furthermore, the HyBurn code has been verified and validated against many test problems including detonations, flames, chemical explosions, and multi-phase blasts. 57–59…”

“…56 Furthermore, the HyBurn code has been verified and validated against many test problems including detonations, flames, chemical explosions, and multi-phase blasts. [57][58][59] Simulations are run using the state-of-the-art high-performance computing (HPC) resource HiPerGator at the University of Florida, where runtimes average around 1200 CPU hours for the HyBurn models generated in this work. Data is post-processed and analyzed using the open-source visualization and graphical analysis software VisIt, and final plots and animations are reformatted using an inhouse Python algorithm.…”