  We assess the robustness of a low Mach number hydrodynamics algorithm for
modeling helium shell convection on the surface of a white dwarf in the context
of the sub-Chandrasekhar model for Type Ia supernovae. We use the low Mach
number stellar hydrodynamics code, MAESTRO, to perform three-dimensional,
spatially-adaptive simulations of convection leading up to the point of the
ignition of a burning front. We show that the low Mach number hydrodynamics
model provides a robust description of the system.
