Phase change materials are substances that absorb and release thermal energy during the process of melting and freezing. This characteristic makes phase change material (PCM)  a favourite choice to integrate it in buildings. Stephan problem including melting and solidification in PMC materials is an practical problem in many engineering processes. The position of the moving boundary, its veloci...

in this paper a method is presented in details to solve a nonlinear partial differential equation which has many applications in engineering fields. the boundary condition is mixed to be able to define the value of function on its variation on the boundary. examples are given to demonstrate the accuracy and efficiency of the method.