Two- and three-dimensional numerical simulations of the hydrodynamic phase of the core helium flash

Two- and three-dimensional models of stellar core helium flashes are extended to the hydrodynamic phase, when convection fails and a runaway occurs. A primitive nuclear reaction network is included, along with transport equations for the various atomic species. Expansion is identified as the primary attenuation mechanism, except in the least violent conditions. A point source model is developed for reducing the computer time necessary for the simulations. The model is applied to inventorying the degeneracy conditions which could lead to the whole range of weak-violent reactions, from carbon burning to supernovae.