Investigation of physiological pulsatile flow in a model arterial stenosis using large-eddy and direct numerical simulations

Paul, M.C. and Molla, M.M. (2012) Investigation of physiological pulsatile flow in a model arterial stenosis using large-eddy and direct numerical simulations. Applied Mathematical Modelling, 36(9), pp. 4393-4413. (doi:10.1016/j.apm.2011.11.065)

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Publisher's URL: http://dx.doi.org/10.1016/j.apm.2011.11.065

Abstract

Physiologicalpulsatileflow in a 3D model of arterialstenosis is investigated by using largeeddysimulation (LES) technique. The computational domain chosen is a simple channel with a biological type stenosis formed eccentrically on the top wall. The physiological pulsation is generated at the inlet using the first harmonic of the Fourier series of pressure pulse. In LES, the large scale flows are resolved fully while the unresolved subgrid scale (SGS) motions are modelled using a localized dynamic model. Due to the narrowing of artery the pulsatileflow becomes transition-to-turbulent in the downstream region of the stenosis, where a high level of turbulent fluctuations is achieved, and some detailed information about the nature of these fluctuations are revealed through the investigation of the turbulent energy spectra. Transition-to-turbulent of the pulsatileflow in the post stenosis is examined through the various numerical results such as velocity, streamlines, velocity vectors, vortices, wall pressure and shear stresses, turbulent kinetic energy, and pressure gradient. A comparison of the LES results with the coarse DNS are given for the Reynolds number of 2000 in terms of the mean pressure, wall shear stress as well as the turbulent characteristics. The results show that the shear stress at the upper wall is low just prior to the centre of the stenosis, while it is maximum in the throat of the stenosis. But, at the immediate post stenotic region, the wall shear stress takes the oscillating form which is quite harmful to the blood cells and vessels. In addition, the pressure drops at the throat of the stenosis where the re-circulated flow region is created due to the adverse pressure gradient. The maximum turbulent kinetic energy is located at the post stenosis with the presence of the inertial sub-range region of slope −5/3.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Molla, Mr M D Mamun and Paul, Dr Manosh
Authors: Paul, M.C., and Molla, M.M.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:Applied Mathematical Modelling
ISSN:0307-904X
Copyright Holders:Copyright © 2012 Elsevier
First Published:First published in Applied Mathematical Modelling
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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