3-DIMENSIONAL BICOMPONENT EXTRUSION SIMULATIONS BY THE BOUNDARY-ELEMENT METHOD

In the present paper the boundary element method is implemented to sol ve fully three-dimensional bi-component flows of Newtonian fluids. The solution formulation follows that of Tran-Cong and Phan-Thien (1988a) . In particular the coextrusion from square and triangular dies is stu died with a view to establishing the dependence of the extrudate shape on viscosity ratio, interface shape, feed ratio and die shape. An ad hoc two-layer model is also investigated which may provide the means t o predict viscoelastic extrudate shape without performing a full visco elastic calculation.