Abstract: To verify whether the polyurethane can be filled in the refrigerator door and observe the volume fraction of the polyurethane at all times, a mathematical model of the flowing filling of polyurethane is established, where with the knowledge of computational fluid dynamics, the writer uses the pre-processing software to divide the actual door model of the refrigerator into grids, and uses fluent software to carry out numerical simulation of polyurethane injection and analysis of pure flow field. The results show that with the filling, the volume fraction of polyurethane increases and the volume fraction of air is gradually replaced. When at 61s or so, the volume fraction of polyurethane reaches the maximum, and polyurethane fills the whole body cavity of the refrigerator door, when the filling process ends.

Key words: Numerical simulation, Injection molding, Volume fraction, Computational fluid dynamics