Publication detail
Influence of Turbulence in Aorta-like Tube: Computational and Experimental Study
JAGOŠ, J. KOHÚT, J. KOTEK, M. SKÁCEL, P. BURŠA, J.
English title
Influence of Turbulence in Aorta-like Tube: Computational and Experimental Study
Type
journal article in Web of Science
Language
en
Original abstract
The presented paper aims at comparison of modelling approaches to a pulsatile fluid flow in aorta-like tube; it investigates their influence on the shape of the velocity profiles and waveforms, and consequently on wall shear stress. Comparisons of computational results between rigid and compliant tubes with laminar and low Re turbulent models of fluid are presented. The results were validated with PIV experimental data through the velocity profile in the half-length section of the tube for both cases (rigid and compliant) and the overall agreement was very good, almost perfect for the rigid case. Frequency of the pulse pump in the experimental circuit was 1Hz, the diameter of the tube similar to 20 mm, and maximum deformation of the compliant tube during a period was 12%. The turbulent model improved the agreement with the experimental data by flattening the velocity profiles in both cases, but the effect was much more pronounced for the compliant tube, especially during the deceleration phase. This work confirms the hypothesis stated by Brindise and Vlachos (2018) that a longer deceleration phase triggers transition to turbulence. We put foundations for extension of this hypothesis to compliant tubes where this conclusion was confirmed for physiological Reynolds and Womersley numbers. The main outputs of this study are: (i) the length of deceleration phase should be considered (in addition to the geometry or severity of stenosis) in decision whether fluid simulations should be performed with or without laminar flow assumption; (ii) for fluid simulations of blood vessels considering their compliance, a special care should be devoted to time synchronization between BCs to prevent unphysiological waveforms.
English abstract
The presented paper aims at comparison of modelling approaches to a pulsatile fluid flow in aorta-like tube; it investigates their influence on the shape of the velocity profiles and waveforms, and consequently on wall shear stress. Comparisons of computational results between rigid and compliant tubes with laminar and low Re turbulent models of fluid are presented. The results were validated with PIV experimental data through the velocity profile in the half-length section of the tube for both cases (rigid and compliant) and the overall agreement was very good, almost perfect for the rigid case. Frequency of the pulse pump in the experimental circuit was 1Hz, the diameter of the tube similar to 20 mm, and maximum deformation of the compliant tube during a period was 12%. The turbulent model improved the agreement with the experimental data by flattening the velocity profiles in both cases, but the effect was much more pronounced for the compliant tube, especially during the deceleration phase. This work confirms the hypothesis stated by Brindise and Vlachos (2018) that a longer deceleration phase triggers transition to turbulence. We put foundations for extension of this hypothesis to compliant tubes where this conclusion was confirmed for physiological Reynolds and Womersley numbers. The main outputs of this study are: (i) the length of deceleration phase should be considered (in addition to the geometry or severity of stenosis) in decision whether fluid simulations should be performed with or without laminar flow assumption; (ii) for fluid simulations of blood vessels considering their compliance, a special care should be devoted to time synchronization between BCs to prevent unphysiological waveforms.
Keywords in English
Pulsatile flow; Pulse wave velocity; Compliant tube; Low Re turbulent model; Boundary condition
Released
01.09.2021
Publisher
Isfahan University of Technology
Location
ISFAHAN
ISSN
1735-3645
Volume
14
Number
5
Pages from–to
1411–1420
Pages count
10
BIBTEX
@article{BUT172470,
author="Jiří {Jagoš} and Jiří {Kohút} and Michal {Kotek} and Pavel {Skácel} and Jiří {Burša},
title="Influence of Turbulence in Aorta-like Tube: Computational and Experimental Study",
year="2021",
volume="14",
number="5",
month="September",
pages="1411--1420",
publisher="Isfahan University of Technology",
address="ISFAHAN",
issn="1735-3645"
}