A New Mathematical Formulation for a Phase Change Problem with a Memory Flux

A mathematical model for a one-phase change problem (particularly a Stefan problem) with a memory flux, is obtained. The hypothesis that the weighted sum of fluxes back in time is proportional to the gradient of temperature is considered. The model obtained involves fractional derivatives with respect on time in the sense of Caputo and in the sense of Riemann–Liouville. An integral relationship for the free boundary which is equivalent to the `fractional Stefan condition’ is also obtained.