Two-phase flow modeling of air entrapment in high pressure die casting considering air compressibility and surface tension. (15th August 2019) - Hao, Jing
Highlights: A two-phase flow model is developed for prediction of air entrapment in HPDC. An ESOLA algorithm for solving the transient two-phase flow is derived. A coupled interface approach VOSET is adopted and extended for capturing interfaces. The importance of considering air compressibility in the model is presented. The influence of surface tension on air entrapment defect is discussed. Abstract: Air entrapment is a serious defect in HPDC (high pressure die casting) process. In this paper a two-phase flow numerical model aimed at predicting this defect is developed. Two important physical factors are firstly considered in the modeling of HPDC process, namely air compressibility and surface tension. An ESOLA (Extended SOLA) algorithm is derived to solve the Navier–Stokes equation of compressible air. An interface capturing approach VOSET (coupled volume of fluid and level set) using geometric operation for level set function is adopted for capturing the melt/air interface evolvement and calculation of surface tension. The proposed model allows calculations with non-orthogonal mesh. The capability of the model is verified by comparing simulation results with analytical and experimental results.