A novel hybrid numerical technique to model 3-D fountain flow in injection molding processes (Q1311356)

A hybrid two-dimensional/three-dimensional numerical technique is presented to examine three-dimensional fountain flow in thin cavities which are encountered in injection molding process. At the flow points, where all the three components of velocity are significant, the authors use a pressure Poisson formulation to solve the equations. Behind the flow front, a two-dimensional Hele-Shaw type formulation is used leading to a ``hammerhead'' approach. Authors have achieved significant reduction in nodes due to the small size of three-dimensional flow region. The governing equations have been solved on a non-staggered grid using boundary fitted coordinate systems in conjunction with the finite difference technique. This formulation is capable of handling material nonlinearities due to shear-thinning behaviour of typical thermoplastic resin systems. Authors have obtained the results for the isothermal filling of diverging and covering cavity sections using a shear-thinning and a Newtonian resin. A comparison with two-dimensional numerical and experimental studies has also been made.