关键词: 注塑成型, 充填模拟, 流动分析, 可压缩流动

Abstract: The flow and heat transfer of the melt in cavity have crucial effects on the final quality and properties of injection-molded parts.In order to predict the shrinkage, warpage and mechanical properties of the injection molded parts, it is necessary to predict the history of flow and heat transfer of melt accurately during the molding process.In this paper, the modeling of filling stage is based on the generalized Hele-Shaw flow of a compressible viscous fluid under non-isothermal conditions with consideration of the effects of compressibility and phase change.A hybrid FEM/FDM was employed to calculate the pressure field and temperature field, and the control volume method was adopted to advance the melt front.The compressible flow analysis of filling stage in plastics injection molding was implemented by using Visual C++.In order to keep each energy term be continuous across inter-element boundaries, each item of energy equation was discretized at the centroid of the elements, and then the energy equation at each vertex node was obtained by a weighted averaging scheme, thus the temperature field was estimated by solving the integrated energy equation of the whole calculation domain.Two parts were analyzed, and the comparison of numerical and experimental results verified the numerical algorithm and program of the compressible filling simulation.The numerical results also indicated that the compressibility of the material had important effects on the flow field of imbalance molds.

Key words: 注塑成型, 充填模拟, 流动分析, 可压缩流动