UNSTEADY-FLOW OF DILUTE FIBER SUSPENSIONS USING A GENERALIZED EULERIAN-LAGRANGIAN APPROACH

In recent years the emphasis on the development of fiber reinforced plastics has experienced an unprecedented expansion, One of the most commonly used methods in manufacturing of plastic products is injection molding. In this work we are using a Generalized Eulerian Lagrangian (GEL) formulation to study the unsteady now of dilute fiber suspensions in injection molding. This formulation combines the advantages of both formulations: in the same flow problem but different regions the GEL formulation allows the selective application of an Eulerian, Lagrangian or a mixture of the two formulations. The suspending fluid is considered to be Newtonian and the contribution of the fibers to the local stress tenser is obtained using a volume averaging theory. The fiber distribution tenser is expressed in terms of a second order tenser with a quadratic closure approximation. Results are shown and discussed for the filling of a cavity from a single gate under different process conditions fibers aspect ratio and content.