NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Numerical simulations of the convective flame in white dwarfsA first step toward better understanding of the mechanism driving convective flames in exploding white dwarfs is presented. The propagation of the convective flame is examined using a two-dimensional implicit hydrodynamical code. The large scales of the instability are captured by the grid while the scales that are smaller than the grid resolution are approximated by a mixing-length approximation. It is found that largescale perturbations (of order of the pressure scale height) do grow significantly during the expansion, leading to a very nonspherical burning front. The combustion rate is strongly enhanced (compared to the unperturbed case) during the first second, but later the expansion of the star suppresses the flame speed, leading to only partial incineration of the nuclear fuel. Our results imply that large-scale perturbations by themselves are not enough to explain the mechanism by which convective flames are driven, and a study of the whole spectrum of relevant perturbations is needed. The implications of these preliminary results on future simulations, in the context of current models for Type Ia supernovae, are discussed.
Document ID
19930049488
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Livne, Eli
(Steward Observatory Tucson, AZ, United States)
Date Acquired
August 16, 2013
Publication Date
March 20, 1993
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 406
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
93A33485
Funding Number(s)
CONTRACT_GRANT: NAGW-2450
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available