A STRONG ENTHALPY FORMULATION FOR THE STEFAN PROBLEM

This paper demonstrates how the condition of constancy with respect to time of the phase-change interface temperature can be incorporated to arrive at a 'strong' enthalpy formulation. The finite-difference solutions obtained with this formulation show that the problem of 'waviness' of the temperature histories encountered with the 'weak' formulation is now removed and accurate solutions are obtained even with a coarse grid irrespective of the time step. The formulation derived requires no 'book-keeping' of the phase-change node, and allows line-by-line integration of the finite-difference equations.