Affiliations: Biomedical Engineering Department, Sahand University of Technology, Tabriz, Iran | Quebec Biomaterial Institute, Québec, G1L 3L5 QC, Canada | Key Lab for Biomechanics & Tissue Engineering of Ministry of Education, Chongqing University, Chongqing 400044, P.R. China
Note: [] Address for correspondence: Dr. Farzan Ghalichi, Department of Biomedical Engineering, Sahand University of Tech‐ nology, Tabriz, Iran. Tel.: +98 411 4245773; E‐mail: [email protected], [email protected].
Abstract: The pulsatile blood flow in a partially blocked artery is significantly altered as the flow regime changes through the cardiac cycle. This paper reports on the application of a low‐Reynolds turbulence model for computation of physiological pulsatile flow in a healthy and stenosed carotid artery bifurcation. The human carotid artery was chosen since it has received much attention because atherosclerotic lesions are frequently observed. The Wilcox low‐Re k–ω turbulence model was used for the simulation since it has proven to be more accurate in describing transition from laminar to turbulent flow. Using the FIDAP® finite element code a validation showed very good agreement between experimental and numerical results for a steady laminar to turbulent flow transition as reported in a previous publication by the same authors. Since no experimental or numerical results were available in the literature for a pulsatile and turbulent flow regime, a comparison between laminar and low‐Re turbulent calculations was made to further validate the turbulence model. The results of this study showed a very good agreement for velocity profiles and wall shear stress values for this imposed pulsatile laminar flow regime. To explore further the medical aspect, the calculations showed that even in a healthy or non‐stenosed artery, small instabilities could be found at least for a portion of the pulse cycle and in different sections. The 40% and 55% diameter reduction stenoses did not significantly change the turbulence characteristics. Further results showed that the presence of 75% stenoses changed the flow properties from laminar to turbulent flow for a good portion of the cardiac pulse. A full 3D simulation with this low‐Re‐turbulence model, coupled with Doppler ultrasound, can play a significant role in assessing the degree of stenosis for cardiac patients with mild conditions.
