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Session 27 - Variable Stars, Novae, & Supernovae.
Display session, Tuesday, June 10
South Main Hall,
In core collapse supernovae (SNe) convection develops beneath the shock due to neutrino heating (from neutrinos emerging from the inner core) and the infall of material toward the core. Based on previous SN simulations it has become clear that the explosion of massive stars may depend on this convection. Studying convection with computer simulations requires understanding how numerical (grid) resolution influences the convection length and time scales involved. In this paper we begin an investigation of these resolution effects for a two-dimensional PPM hydrodynamics code.
We present numerical simulations of convection in the outer layers of a supernova. These simulations were performed with VH-1, a PPMLR hydrodynamics code, on a two-dimensional grid, using spherical coordinates. The initial data and boundary conditions for these calculations are derived from the output of one-dimensional supernova simulations that implement multigroup flux-limited diffusion (MGFLD). Grid resolutions (N_r \times N_\theta) of 128^2, 256^2, and 512^2 are used to study the dependence of convection on numerical resolution. The time-evolution of various diagnostics, such as vorticity, root-mean-square theta velocity, and Fourier transforms of density, will be displayed. All simulations were done on the North Carolina Supercomputing Center's Cray T90.
Program listing for Tuesday