NUMERICAL-SIMULATION OF NONISOTHERMAL EXTRUDATE SWELL AT HIGH EXTRUSION RATES

Non-isothermal extrudate swell problems for viscoelastic fluids have b een solved by employing a modified non-consistent streamline upwind mi xed finite element method with the White-Metzner constitutive equation . The computation was shown to be stable and to converge up to extrusi on rates significantly higher than those used in previous studies whic h employed conventional finite element methods. Additionally, the effe cts of viscous dissipation at high extrusion rates and various cooling rates have been discussed. Furthermore, the effects of two kinds of a rtificial diffusivities and various forms of material functions on the swell ratio and the free surface profiles have been discussed. The ex trudate swell has been shown to exhibit an important temperature depen dence.