ON THE SELECTION OF PARAMETERS IN THE FENE-P MODEL

We compare the FENE and FENE-P models in different flow situations. We start with Brownian dynamics simulations of start-up of shear and uni axial elongational flow. The FENE-P model predicts the FENE behaviour unsatisfactorily. However, we will show that its performance can be su bstantially improved. We propose to determine the parameters in the FE NE-P model such that important FENE flow characteristics are recovered . The three resulting models (FENE, FENE-P and the proposed FENE-P mod el) will first be compared in the above-mentioned rheometrical flows. To show that the improvement persists in a complex how field, we also simulate the flow of the FENE fluid past a cylinder using the Brownian configuration held technique. We then compare the results with those of the proposed FENE-P model and those of the original FENE-P model. ( C) 1998 Elsevier Science B.V. All rights reserved.