Numerical analysis of melting/solidification phenomena using a moving boundary problem analysis method X-FEM

Uchibori, Akihiro ; Ohshima, Hiroyuki

A numerical analysis method for melting/solidification phenomena has been developed to evaluate feasibility of the several candidate techniques in the nuclear fuel cycle. Our method is based on the eXtended Finite Element Method (X-FEM) which has been used for moving boundary problems. The basic idea of the X-FEM is to incorporate the signed distance function into the standard finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. This technique makes it possible to simulate movement of the solid-liquid interface without the use of a moving mesh. The numerical solutions of the basic problems, a one-dimensional Stefan problem, solidification in a two-dimensional square corner and melting of pure gallium, were compared to the exact solutions or to the experimental data. Through these verifications, validity of the newly developed numerical analysis method has been demonstrated.