Hysteretic behavior of a moment-closure approximation for FENE model

摘要: We discuss hysteretic behaviors of dilute viscoelastic polymeric fluids with moment-closure approximation approach in extensional/enlongational flows. Polymeric fluids are modeled by the finite extensible nonlinear elastic (FENE) spring dumbbell model. Hysteresis is one key features to describe FENE model. We here investigate behavior FENE-D model introduced [Y. Hyon et al., Multiscale Model. Simul., 7(2008), pp.978--1002]. The established from a special equilibrium solution Fokker-Planck equation to catch extreme large extensional flow rates. Since hysteresis can be seen during relaxation simple flow employing normal stress/the elongational viscosity versus mean-square extension, we simulate flows its comparing to FENE-P, FENE-L [G. Lielens J. Non-Newtonian Fluid Mech., 76(1999), pp.249--279]. The FENE-P well-known pre-averaged approximated model, and it shows good agreement macroscopic induced stresses. However, does not any phenomenon. In contrast, better than other models FENE, but has limitation for stresses shear rates. On hand, presents even rates, and moreover, phenomenon certain rates.