| A computer-aided engineering analysis (CAE) tool has been developed for injection molding of polymers and investment casting of metals. Although the flow characteristics of polymers and liquid metals are at the opposite ends of Navier-Stokes spectrum, we have exploited the common features and added necessary extensions to develop accurate and efficient numerical procedures for both the processes. The primary features of the numerical scheme are (1) calculation of pressure or velocity potential using the finite element method, (2) advancement of the flow front using the control volume technique, and (3) temperature calculation using the finite difference method. A coordinate transformation to handle the complex three dimensional geometries, a special upwinding scheme for the triangular element to alleviate the stringent numerical stability criteria, and a domain decomposition method for the reduction of the computation time have also been developed.; Numerical results have been obtained for a range of part geometries and compared with both available experiments and existing numerical simulations. Specifically, for injection molding process the numerical results were compared with the analytically calculated pressure gradient, experimental short shots, and experimental measurements of pressure. In the case of casting process, the emphasis has been on the prediction of the flow field, and the comparison with experimental filling patterns for a rectangular geometry were made. In general, the numerical simulation has shown good agreement providing validation of the numerical approximations and the physical description of the problems. |
