Analysis of Nonisothermal Extrudate Swell

Nonisothermal extudate swell through capillary and annular dies was studied numerically using a control volume finite difference method. In order to examine the effect of the relevant dimensionless parameters on the swelling behavior of the extrudate, Newtonian liquids having a temperature dependent viscosity have been chosen and computations have been performed for various process conditions. Four dimensionless groups, i.e., the Peclet number (Pe), the Brinkman number (Br) the Biot number (Bi), and an exponential parameter β expressing the temperature dependence of viscosity, were examined respectively, and the sensitivity of each group on the swelling ratio was determined. The parameter β was found to be the most sensitive factor.