A FREE-FRONT TRACKING ALGORITHM FOR A CONTROL-VOLUME-BASED HELE-SHAW METHOD

With free surface flow problems the position of the free front at a pa rticular time step needs to be predicted. When simulating the flow of hot molten polymer in injection moulds this position is essential for the prediction of the position of the weld lines on the final product. Weld lines are important in that they indicate positions of diminishe d strength and spoil the aesthetics of the product. A code using a fin ite volume approach on the thin gap Hele-Shaw flow equations to simula te the filling stage of the injection moulding process has been develo ped which requires a suitable algorithm for the free-front tracking. T he Volume of Fluid (VOF) method was implemented in this study for the tracking of the free front. The discretization and various formulation s of the VOF equation are presented as well as the results obtained. T he impact on the existing equations is also investigated as well as th e development of a packing routine that is used to eliminate the diffu sive nature of the VOF equation. (C) 1998 John Wiley & Sons, Ltd.