1999/06/30 by J. C. Niemeyer · 5 citations
Engineering · Physics and Astronomy · #Amplitude #Combustion and Detonation Processes #Energetic Materials and Combustion #Gamma-ray bursts and supernovae #Laminar flow #Supernova #Temperature gradient #Thermonuclear fusion #Turbulence #Type (biology) #astro-ph
paper · pdf · doi:10.1086/312253
8 pages, uses aastex; added references. Accepted by ApJ Letters
arxiv created 1999/07/19 · openalex publication_date 1999/09/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The mechanism for a deflagration-detonation transition (DDT) by turbulent preconditioning, which has previously been used to explain the possible occurrence of delayed detonations in Type Ia supernova explosions, is argued here to be conceptually inconsistent. It relies crucially on diffusive heat losses of the burned material on macroscopic scales. Regardless of the amplitude of the turbulent velocity fluctuations, the typical gradient scale for the temperature fluctuations is shown to be of the order of the laminar flame width or smaller rather than the homogeneity scale required for DDT, which is larger by more than a factor of 1000. Furthermore, thermonuclear flames cannot be fully quenched in regions that are much larger than the laminar flame width as a consequence of their simple "chemistry." Possible alternative explosion scenarios are briefly discussed.