## Joseph M. Powers - Detailed and reduced modeling of reacting fluid mechanics

*The simulation of a reacting mixture of ideal gases is considered. The competition between advection, reac- tion, and diffusion in an unsteady spatially inhomogeneous geometry often induces phenomena which evolve on multiple length and time scales. While the continuum model equations are generally well accepted, ana- lytical solutions are generally not available, and computational solution is difficult due to the plethora of scales. It is demonstrated that a detailed solution of the model equations is able to capture some of the ob - servable harmonies in nature; in particular, predictions of oscillating detonations in a hydrogen-air mixture are able to match well with experiment. Also discussed are reduction strategies for systematically removing stiffness from reacting systems in the absence of advection and diffusion.*

14/12/2023