Stability of Flame-Shock Coupling in Detonation Waves: 1D Dynamics (Preprint)
Abstract
The study of detonation waves dates back to the late 19th century, where Chapman and Jouguet modeled detonations as a shock wave supported by the heat release of the combustible material in an infinitely thin zone, where all chemistry and diffusive transport takes place. Later Zel'dovich, von Neumann, and Doring independently represented the detonation as a confluence of a shock wave moving at a detonation velocity, followed by a chemical reaction zone of finite length; this came to be known as the ZND model for a detonation wave. While the true structure of detonation waves inevitably calls for multidimensional effects, the simple 1D structure still provides a rich spectrum of dynamical features which are worthy of detailed exploration. This is especially important for the study of deflagration to detonation transitions and sustained oscillating or galloping detonations. For a spark-induced detonation, as the detonation decays towards the self-sustaining Chapman-Jouguet mode from an over-driven mode, one obtains a sequence of physical oscillations between the flame and shock front. The numerical analysis of this effect has been explored by Cambier, using highly-resolved numerical simulations, albeit with only a 2nd-order shock capturing scheme. Similar calculations of the dynamics of detonation oscillations, albeit with a reduced chemistry model, have been performed elsewhere. In the present study, we utilize high-order spatially accurate numerical methods in order to achieve grid convergence and to reduce or eliminate numerical diffusion effects while providing a detailed analysis of the nonlinear dynamics involved in resolving detonations with complex reaction kinetics. The dynamical characteristics and coupling of large and small length scale physics associated with detonation instabilities are explored in detail.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2011
- Accession Number
- ADA554887
Entities
People
- Ann Karagozian
- Jean Luc Cambier
- Lord K. Cole
Organizations
- Air Force Research Laboratory