Title: Large-eddy simulation of pulsatile non-Newtonian flow in a constricted channel

Authors: Md. Mamun Molla; Afzal Hossain; Bing-Chen Wang; David C.S. Kuhn

Addresses: Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6, Canada. ' Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6, Canada. ' Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6, Canada. ' Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6, Canada

Abstract: In this research, we numerically investigate the physics of a pulsatile non-Newtonian flow confined within a three-dimensional (3D) channel with an idealised stenosis formed eccentrically on the upper wall using the method of large-eddy simulation (LES). A new consistent modelling approach is proposed to perform LES of non-Newtonian flow by implementing the advanced subgrid-scale (SGS) stress model of Wang and Bergstrom (2005) in the current numerical procedure. The proposed modelling approach for LES resolves the previous conceptual inconsistency in modelling the molecular and SGS viscosities, as it warrants that both the molecular and SGS viscosities are non-linear functions of the resolved strain rate tensor. The Womersley number tested in the simulation is fixed at 10.5 and the Reynolds number tested is set to 1200, which are characteristics of human blood flows in large arteries. An in-house 3D LES code has been modified to conduct our unsteady numerical simulations, and the results obtained have been validated using two different grid arrangements and reported experimental data.

Keywords: biofluids; non-Newtonian flow; fluid flow; large-eddy simulation; LES; subgrid-scale modelling; transition flow; turbulence; pulsatile flow; constricted channels; stress models; human blood flow; large arteries.

DOI: 10.1504/PCFD.2012.048253

Progress in Computational Fluid Dynamics, An International Journal, 2012 Vol.12 No.4, pp.231 - 242

Published online: 25 Nov 2014 *

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