Cargando…

An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids

Numerical flow simulations play an important role in polymer processing. One of the essential prerequisites for accurate and precise flow simulations is to obtain accurate materials functions. In the framework of the generalized Newtonian fluid model, one needs to obtain shear viscosity as a functio...

Descripción completa

Detalles Bibliográficos
Autores principales: Amangeldi, Medeu, Wang, Yanwei, Perveen, Asma, Zhang, Dichuan, Wei, Dongming
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8659470/
https://www.ncbi.nlm.nih.gov/pubmed/34883688
http://dx.doi.org/10.3390/polym13234185
_version_ 1784612969929244672
author Amangeldi, Medeu
Wang, Yanwei
Perveen, Asma
Zhang, Dichuan
Wei, Dongming
author_facet Amangeldi, Medeu
Wang, Yanwei
Perveen, Asma
Zhang, Dichuan
Wei, Dongming
author_sort Amangeldi, Medeu
collection PubMed
description Numerical flow simulations play an important role in polymer processing. One of the essential prerequisites for accurate and precise flow simulations is to obtain accurate materials functions. In the framework of the generalized Newtonian fluid model, one needs to obtain shear viscosity as a function of the rate-of-shear and temperature—as determined by rheometry—and then fitted to a mathematical model. Often, many subjectively perform the fitting without paying attention to the relative quality of the estimated parameters. This paper proposes a unique iterative algorithm for fitting the rate-of-shear and temperature-dependent viscosity model under the time–temperature superposition (TTS) principle. Proof-of-concept demonstrations are shown using the five-parameter Carreau–Yasuda model and experimental data from small-amplitude oscillatory shear (SAOS) measurements. It is shown that the newly proposed iterative algorithm leads to a more accurate representation of the experimental data compared to the traditional approach. We compare their performance in studies of the steady isothermal flow of a Carreau–Yasuda model fluid in a straight, circular tube. The two sets of parameters, one from the traditional approach and the other from the newly proposed iterative approach, show considerable differences in flow simulation. The percentage difference between the two predictions can be as large as 10% or more. Furthermore, even in cases where prior knowledge of the TTS shifting factors is not available, the newly proposed iterative approach can still yield a good fit to the experimental data, resulting in both the shifting factors and parameters for the non-Newtonian fluid model.
format Online
Article
Text
id pubmed-8659470
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-86594702021-12-10 An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids Amangeldi, Medeu Wang, Yanwei Perveen, Asma Zhang, Dichuan Wei, Dongming Polymers (Basel) Article Numerical flow simulations play an important role in polymer processing. One of the essential prerequisites for accurate and precise flow simulations is to obtain accurate materials functions. In the framework of the generalized Newtonian fluid model, one needs to obtain shear viscosity as a function of the rate-of-shear and temperature—as determined by rheometry—and then fitted to a mathematical model. Often, many subjectively perform the fitting without paying attention to the relative quality of the estimated parameters. This paper proposes a unique iterative algorithm for fitting the rate-of-shear and temperature-dependent viscosity model under the time–temperature superposition (TTS) principle. Proof-of-concept demonstrations are shown using the five-parameter Carreau–Yasuda model and experimental data from small-amplitude oscillatory shear (SAOS) measurements. It is shown that the newly proposed iterative algorithm leads to a more accurate representation of the experimental data compared to the traditional approach. We compare their performance in studies of the steady isothermal flow of a Carreau–Yasuda model fluid in a straight, circular tube. The two sets of parameters, one from the traditional approach and the other from the newly proposed iterative approach, show considerable differences in flow simulation. The percentage difference between the two predictions can be as large as 10% or more. Furthermore, even in cases where prior knowledge of the TTS shifting factors is not available, the newly proposed iterative approach can still yield a good fit to the experimental data, resulting in both the shifting factors and parameters for the non-Newtonian fluid model. MDPI 2021-11-30 /pmc/articles/PMC8659470/ /pubmed/34883688 http://dx.doi.org/10.3390/polym13234185 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Amangeldi, Medeu
Wang, Yanwei
Perveen, Asma
Zhang, Dichuan
Wei, Dongming
An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids
title An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids
title_full An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids
title_fullStr An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids
title_full_unstemmed An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids
title_short An Iterative Approach for the Parameter Estimation of Shear-Rate and Temperature-Dependent Rheological Models for Polymeric Liquids
title_sort iterative approach for the parameter estimation of shear-rate and temperature-dependent rheological models for polymeric liquids
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8659470/
https://www.ncbi.nlm.nih.gov/pubmed/34883688
http://dx.doi.org/10.3390/polym13234185
work_keys_str_mv AT amangeldimedeu aniterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT wangyanwei aniterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT perveenasma aniterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT zhangdichuan aniterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT weidongming aniterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT amangeldimedeu iterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT wangyanwei iterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT perveenasma iterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT zhangdichuan iterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids
AT weidongming iterativeapproachfortheparameterestimationofshearrateandtemperaturedependentrheologicalmodelsforpolymericliquids