  We develop and calibrate a realistic model flame for hydrodynamical
simulations of deflagrations in white dwarf (Type Ia) supernovae. Our flame
model builds on the advection-diffusion-reaction model of Khokhlov and includes
electron screening and Coulomb corrections to the equation of state in a
self-consistent way. We calibrate this model flame--its energetics and
timescales for energy release and neutronization--with self-heating reaction
network calculations that include both these Coulomb effects and up-to-date
weak interactions. The burned material evolves post-flame due to both weak
interactions and hydrodynamic changes in density and temperature. We develop a
scheme to follow the evolution, including neutronization, of the NSE state
subsequent to the passage of the flame front. As a result, our model flame is
suitable for deflagration simulations over a wide range of initial central
densities and can track the temperature and electron fraction of the burned
material through the explosion and into the expansion of the ejecta.
