Effect of rheologocal properties of polymer melts on kinematics of their flows in converging channeles | Vestnik Tomskogo gosudarstvennogo universiteta. Matematika i mekhanika – Tomsk State University Journal of Mathematics and Mechanics. 2025. № 98. DOI: 10.17223/19988621/98/12

Effect of rheologocal properties of polymer melts on kinematics of their flows in converging channeles

This study uses a modified Vinogradov-Pokrovsky rheological model to investigate two-dimensional flows of polymer melts with different molecular structures in channels with a rectangular cross-section and a sudden contraction. The effect of the polymer structure on the flow behavior is analyzed. It is shown that the branched polymer exhibits a reverse flow in the entrance region of the slit channel, whereas the linear polymer does not induce secondary flows. This effect is found to be governed by the polymer relaxation time, i.e., the Weissenberg number. The profiles of the x- and y-components of the velocity vector are examined in several cross-sections upstream of the slit channel and within the channel. For the branched polymer, the x-component of the velocity takes both positive and negative values, and the y-compo-nent is directed away from the channel axis, which indicates the presence of a reverse flow. The branched polymer demonstrates a non-parabolic velocity profile in the slit channel, in contrast to the linear polymer, whose velocity distribution is close to parabolic. In all the considered cases, the computed velocity profiles are compared with the experimental data. The obtained results confirm the applicability of the modified Vinogradov-Pokrovsky rheological model for describing non-uniform flows of polymer melts, as well as the efficiency of finite-element-based computational methods for simulating unsteady two-dimensional flows of nonlinear viscoelastic media with a rheological law written in a differential form.

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Keywords

rheology, viscosity, polymer melts, vortex flow, rheological equation of state, two-dimensional flows, finite element method

Authors

Name	Organization	E-mail
Pavlov Mikhail S.	Tomsk Polytechnical University	mspavlov@tpu.ru
Pavlyuk Yuriy A.	Altai State Pedagogical University	pawlyk1996@yandex.ru
Pyshnograi Grigoriy V.	Altai State Technical University	pyshnograi@mail.ru

Всего: 3

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