Simulation of Fountain Flow based on Molecular Dynamics Method

Abstract

In this paper, numerical simulations of the fountain effect on the flow front of polymer dilute solutions are carried out based on molecular dynamics principles and the FENE dumbbell model. The Euler method is used to solve the constitutive equations of the mechanical model for the simple shear flow field and the dislocation equations of the dumbbell molecules, and subsequently obtain the tracer flow lines and the dumbbell distribution of the flow front. The results are used to calculate the stress field, analyze the rheological evolution law, study the effect of temperature and shear rate and other parameters on the model and analyze the effectiveness of the FENE dumbbell molecular model for the fountain effect. The study shows that due to the fountain effect the dumbbell molecules stretch more with increasing shear rate, the polymer stress at the flow front will show a complex change of stress overshoot and then stabilize, and the dumbbell molecules are oriented along the fountain flow line.