Utilizing the Discrete Element Method for the modeling of viscosity in concentrated suspensions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F16%3A43902724" target="_blank" >RIV/60461373:22340/16:43902724 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.langmuir.6b02335" target="_blank" >http://dx.doi.org/10.1021/acs.langmuir.6b02335</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.langmuir.6b02335" target="_blank" >10.1021/acs.langmuir.6b02335</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Utilizing the Discrete Element Method for the modeling of viscosity in concentrated suspensions

Popis výsledku v původním jazyce

The rheological behavior of concentrated suspensions is a complicated problem, because it originates in the collective motion of particles and their interaction with the surrounding fluid. For this reason, it is difficult to accurately model the effect of various system parameters on the viscosity even for highly simplified systems. We model the viscosity of a hard-sphere suspension subjected to high shear rates using the dynamic Discrete Element Method (DEM) in three spatial dimensions. The contact interaction between particles was described by the Hertz model of elastic spheres (soft-sphere model) and the interaction of particles with flow was accounted for by the two-way coupling approach. The hydrodynamic interaction between particles was described by the lubrication theory accounting for the slip on particle surface. The viscosity in a simple-shear model was evaluated from the force balance on the wall. Obtained results are in close agreement with literature data for systems with hard spheres. Namely, the viscosity is shown to be independent of shear rate and primary particle size for monodisperse suspension. In accordance with theory and experimental data, the viscosity grows rapidly with particle volume fraction. We show that this rheological behavior is predominantly caused by the lubrication forces. A novel approach based on the slip of water on particle surface was developed to overcome the divergent behavior of lubrication forces. This approach was qualitatively validated with literature data from AFM measurements using a colloidal probe. The model presented in this work represents a new, robust and versatile approach to the modeling of viscosity in suspensions with the possibility to include various interaction models and to study their effect on viscosity.

Název v anglickém jazyce

Utilizing the Discrete Element Method for the modeling of viscosity in concentrated suspensions

Popis výsledku anglicky

The rheological behavior of concentrated suspensions is a complicated problem, because it originates in the collective motion of particles and their interaction with the surrounding fluid. For this reason, it is difficult to accurately model the effect of various system parameters on the viscosity even for highly simplified systems. We model the viscosity of a hard-sphere suspension subjected to high shear rates using the dynamic Discrete Element Method (DEM) in three spatial dimensions. The contact interaction between particles was described by the Hertz model of elastic spheres (soft-sphere model) and the interaction of particles with flow was accounted for by the two-way coupling approach. The hydrodynamic interaction between particles was described by the lubrication theory accounting for the slip on particle surface. The viscosity in a simple-shear model was evaluated from the force balance on the wall. Obtained results are in close agreement with literature data for systems with hard spheres. Namely, the viscosity is shown to be independent of shear rate and primary particle size for monodisperse suspension. In accordance with theory and experimental data, the viscosity grows rapidly with particle volume fraction. We show that this rheological behavior is predominantly caused by the lubrication forces. A novel approach based on the slip of water on particle surface was developed to overcome the divergent behavior of lubrication forces. This approach was qualitatively validated with literature data from AFM measurements using a colloidal probe. The model presented in this work represents a new, robust and versatile approach to the modeling of viscosity in suspensions with the possibility to include various interaction models and to study their effect on viscosity.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CI - Průmyslová chemie a chemické inženýrství

OECD FORD obor

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Projekt

<a href="/cs/project/GA16-22997S" target="_blank" >GA16-22997S: Příprava porézních materiálú pomocí kontrolovaného uspořádání nanočástic</a><br>

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Langmuir

ISSN

0743-7463

e-ISSN

—

Svazek periodika

32

Číslo periodika v rámci svazku

33

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

8451-8460

Kód UT WoS článku

000381959200018

EID výsledku v databázi Scopus

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