关键词: 残余壁厚, 两相流, 数值模拟, 水辅成型, 水针

Abstract: Residual wall thickness is an important indicator to measure the quality of water-assisted injection molding (WAIM). Computational fluid dynamics (CFD) approach is used to simulate the residual wall thickness formation of non-circular cross-section parts. The simulation result is compared with the experiment result, which shows good agreement between the two, thus verifying the accuracy of the simulation model. The results also show that the cross-section geometry has great influence on residual wall thickness. The residual wall thickness decreases obviously with the increase of the cross-section circle-ratio, which indicates that the WAIM is more suitable for the production of parts with large cross-section circle-ratio. System holding-pressure and water flow penetration length affect the residual wall thickness. The increase of the holding pressure can help decrease the residual wall thickness. The increase of water flow penetration length on the one hand makes the residual wall thickness tend to increase, and on the other hand promotes uniform distribution of the residual wall thickness. The research has a strong guiding significance for the study of WAIM process.

Key words: Numerical simulation, Residual wall thickness, Two-phase flow, Water injection pin, Water-assisted injection molding