Institute for Advanced Study Informal Astrophysics Seminar

ABSTRACT: DDTs are observed in terrestrial combustion flows, and are inferred to occur in supernova explosions of type Ia. The physical mechanism responsible for DDT, in both chemical and nuclear combustion, is a long standing open question. We propose (arXiv:1108.4690) a novel mechanism for the transition, showing that detonation may be ignited by converging shocks in nearly sonic turbulent deflagration flows. The suggested mechanism is an alternative to the one proposed by Zeldovich et al. (1970), in which finely tuned spatial gradients in the combustible medium must be maintained in the turbulent deflagration flow. The model makes predictions that may be tested by both terrestrial experiments and numerical simulations.