Hence, the evolution of mathematical analyses on solidification and melting problems
has undergone three distinct eras. Most of the earlier investigations were confined
to one-dimensional diffusion-controlled problems with very simple geometries due to
constraints in the tools available to scientists and engineers at that time. The analytical
solutions developed during this first era serve as a cornerstone of this discipline and are
still used today as standard references to validate the numerical models. The advent
of computers, a couple of decades ago, enabled the consideration of multidimensional
problems with more complex geometries. A new era of analysis in the solidification
and melting problems commenced with the birth of numerical methods. Perhaps owing
to the limited power of the earlier computers, the numerical models in the second
era that were developed were based on one equation (e.g., and energy or diffusion
equation) and omission of convection. With the help of the more advanced and powerful
computers which have been developed in the past decade, mathematical modelling has
proceeded into a modern era. More sophisticated numerical models have been developed
374 H Hu and A Argyropoulos
to handle multidimensional phenomena involving convection as well as the presence of
the moving boundary in complex geometries. The succeeding review will summarize
the major developments in mathematical analyses of the phase change problems involved
in melting and solidification phenomena. The intention of this review is to present and
compare some of the well known and novel numerical methods available to solve phase
change problems since it is impossible to review all the existing methods within one
article.