Geometry of the flame surface for different values of the asymmetry diagnostic parameter ζ (1). The plot for ζ = 0 is a snapshot of the H01 simulation at 320 ms of simulated time; the flame surface is essentially a sphere due to the suppression of the Rayleigh-Taylor instability. All of the other plots are of the J01 simulation. The time evolution of ζ is shown in Fig. 8; the asphericity becomes more pronounced with time in the G and J series simulations. Each panel also has a pseudo-colour plot of the electron fraction Y_e.