Computational Astrophysical Fluid Dynamics

Computational fluid dynamics, indeed all computation, is easy enough when there are no large or small parameters in the problem, but this is unfortunately rarely the case in astrophysics. Although much can be achieved by the intelligent use of dimensional analysis in order to rescale the problem, this is seldom enough to carry out interesting computations on a uniform grid and there is little prospect that increases in computer power can do much to alleviate this in the near future. It is, however, possible to construct hydrodynamic codes that use a hierarchical grid to achieve high resolution in places where the solution varies rapidly and this, combined with rescaling, enormously extends the range of problems that can be tackled. The power of these methods is illustrated by the applying them to the propagation of detonations in Type Ia supernovae.