FINITE ELEMENT TECHNIQUE FOR PHASE-CHANGE HEAT CONDUCTION PROBLEM

摘要

Liquid-solid phase transition is accompanied by a latent heat release, both in isothermal and non-isothermal phase transformations. The latent heat and the discontinuous phase change function increase the difficulty of obtaining a solution for the Fourier heat conduction equation. Celentano et al. [Int. J. Nu-mer. Meth. Eng. 37(20), 1994] proposed a temperature-based finite element model for solving multidimensional transient heat conduction involving phase change. The present work addresses the computational aspects of the Celentano et al. model. The importance of a line search algorithm for improving the convergence of the Newton-Raphson iterations are explained in detail. While performing the iterations in this kind of fixed domain methods, the phase front moves back and forth fictitiously. The introduced phase change matrix handles the latent effect efficiently. The phase fractions are evaluated at the integration points instead of the nodal points. Several numerical examples are presented and the benefits and difficulties of the solution technique are elaborately discussed.