PETROV-GALERKIN FINITE-ELEMENT ANALYSIS FOR ADVANCING FLOW FRONT IN REACTION INJECTION-MOLDING

A numerical scheme for computing the advancement of a flow front and r elated velocity, pressure, conversion and temperature distributions du ring mold filling in reaction injection molding (RIM) is described in this work. In the RIM process, the convective term in the energy equat ion is dominant. Therefore, the numerical scheme has incorporated a Pe trov-Galerkin finite element method to suppress spurious oscillations and to improve accuracy of the calculations. The other feature of the numerical scheme is that the flow front locations are computed simulta neously with primary variables by using a surface parameterization tec hnique. The numerical results compare well with the reported experimen tal data. Improved accuracy obtained by this numerical scheme in the f low front region is expected to assist in the predictions of the fiber orientations and the bubble growth in RIM, which are determined prima rily by the flow front region.