AbstractPredicting interface position of solid‐liquid phase change is important for the filling of explosives in the shell. The cooling process of casting charge is discussed analytically and experimentally. The basic equations describing this process are derived from a modified and extended equivalent heat capacity model. Numerical calculations are then performed to determine the solidification front distributions and temperature distributions. The experiments are performed using TNT as the phase change material. Comparison between practical experiments and computer simulation has shown that there is a good agreement. By using computer calculations, a better knowledge of important parameters for the casting process can be easily obtaine