Influence of stenosis severity on hemodynamics flow at low Reynolds numbers: A computational fluid dynamic study
A computational fluid dynamic study
Keywords:
cardiovascular disease, CFD, Hemodynamics flow, Stenotic arteries, Flow disturbanceAbstract
The restriction of blood flow due to narrowing of arteries that supply blood to different parts of the body leads to high blood pressure and cholesterol in humans. In this study, blood flow in a 3D model of arterial stenosis was examined using computational fluid dynamics (CFD) technique. The geometry of the stenosis was modeled using ANSYS software, and a structured tetrahedral mesh was generated for accurate representation. The CFD analysis was performed using the ANSYS (FLUENT) 19.2 commercial code to investigate three stenosis levels of 75%, 50%, and 25% over the Reynolds number range of 500-2000 with blood as the working fluid. The blood flowed steadily upstream of the stenosis as incompressible, homogeneous, and Newtonian, while the artery is considered to be inflexible. The Reynolds-averaged Navier-Stokes equations and the low Reynolds number SST k-ω turbulence model were employed to simulate the blood flow. The governing equations are solved, and the pressure-velocity coupling is handled using the SIMPLEC algorithm. The steady state velocity and pressure generated at the inlet and outlet of the artery enabled the hemodynamic properties and flow reversal through arteries with a progressive amount of atherosclerosis to be determined. The results are presented in terms of velocity distribution, streamlines, and turbulence intensity contours. The results showed that at the throat (Z = 0) of the 75% stenosis, the relative magnitude of the velocity is greater than or equal to four times the average velocity. Reversal of flow is visible at for Re = 500 and for Re = 750 and Re = 2000. Furthermore, the effects of 25% stenosis on the flow pattern are relatively blunt and weak at . The throat of the stenosis, or a site therein, exhibits the highest value of centerline velocity, while turbulence intensity becomes severe at the post-stenotic site and they both increase with increasing stenosis level. The study provides valuable insights into the velocity distribution, flow reversal phenomenon, and turbulence intensity in arterial stenosis. The findings highlight the significant impact of stenosis levels and Reynolds numbers on the hemodynamic behavior, offering important considerations for understanding and managing arterial health issues.
References
Ahmed, S. A. and Giddens, D. P. (1983). Velocity measurements in steady flow through axisymmetric stenoses at moderate Reynolds numbers. Journal of Biomechanics, 16(7): 505–516. doi: 10.1016/0021-9290(83)90065-9.
Ahmed, S. A. and Giddens, D. P. (1984). Pulsatile poststenotic flow studies with laser Doppler anemometry. Journal of Biomechanics, 17(9): 695–705. doi: 10.1016/0021-9290(84)90123-4.
Banks, J. and Bressloff, N. W. (2007). Turbulence Modeling in Three-Dimensional Stenosed Arterial Bifurcations. Journal of Biomechanical Engineering, 129(1): 40–50. doi: 10.1115/1.2401182.
Cassanova, R. A. and Giddens, D. P. (1978). Disorder distal to modeled stenoses in steady and pulsatile flow. Journal of Biomechanics, 11(10–12): 441–453. doi: 10.1016/0021-9290(78)90056-8.
Clark, C. (1976). Turbulent velocity measurements in a model of aortic stenosis. Journal of Biomechanics, 9(11): 677–687. Available at: https://www.sciencedirect.com/science/article/pii/002192907690169X (Accessed: 29 September 2022).
Clark, C. (1977). Turbulent wall pressure measurements in a model of aortic stenosis. Journal of Biomechanics, 10(8): 461–472. doi: 10.1016/0021-9290(77)90100-2.
Deshpande, M. D. and Giddens, D. P. (1980). Turbulence measurements in a constricted tube. Journal of Fluid Mechanics, 97(1): 65–89. doi: 10.1017/S0022112080002431.
Deshpande, M. D., Giddens, D. P. and Mabon, R. F. (1976). Steady laminar flow through modelled vascular stenoses, Journal of Biomechanics, 9(4): 165–174. doi: 10.1016/0021-9290(76)90001-4.
Dietiker, J. F. and Hoffmann, K. A. (2006). Computation of three-dimensional blood flows in arteries. Collection of Technical Papers - 36th AIAA Fluid Dynamics Conference, 2: 797–811. doi: 10.2514/6.2006-3213.
Khalifa, M. A. and Giddens, D. P. (1981). Characterization and evolution of poststenotic flow disturbances. Journal of Biomechanics, 14(5): 279–296. doi: 10.1016/0021-9290(81)90038-5.
Liao, W., Lee, T. S. and Low, H. T. (2011). Numerical study of physiological turbulent flows through stenosed arteries. International Journal of Modern Physics C, 14(05): 635-659. doi: 10.1142/S0129183103004838.
Mathieu, J. and Scott, J. (2000). An introduction to turbulent flow.
Mittal, R., Simmons, S. P. and Najjar, F. (2003). Numerical study of pulsatile flow in a constricted channel. Journal of Fluid Mechanics, 485: 337–378. doi: 10.1017/S002211200300449X.
Ojha, M. et al. (1989). Pulsatile flow through constricted tubes: an experimental investigation using photochromic tracer methods. Journal of Fluid Mechanics, 203(173): 173–197. doi: 10.1017/S0022112089001424.
Ryval, J., Straatman, A. G. and Steinman, D. A. (2004). Two-equation Turbulence Modeling of Pulsatile Flow in a Stenosed Tube. Journal of Biomechanical Engineering, 126(5): 625–635. doi: 10.1115/1.1798055.
Tobin, R. J. and Chang, I. D. (1976). Wall pressure spectra scaling downstream of stenoses in steady tube flow. Journal of Biomechanics, 9(10): 633–640. doi: 10.1016/0021-9290(76)90105-6.
Varghese, S. S., Frankel, S. H. and Fischer, P. F. (2007a). Direct numerical simulation of stenotic flows. Part 1. Steady flow. Journal of Fluid Mechanics, 582: 253–280. doi: 10.1017/S0022112007005848.
Varghese, S. S., Frankel, S. H. and Fischer, P. F. (2007b). Direct numerical simulation of stenotic flows. Part 2. Pulsatile flow. Journal of Fluid Mechanics, 582: 281–318. doi: 10.1017/S0022112007005836.
World Health Organization. (2011). Global atlas on cardiovascular disease prevention and control: published by the World Health Organization in collaboration with the World Heart Federation and the World Stroke Organization. World Health Organization. Regional Office for Europe.
Downloads
Published
Issue
Section
License
Copyright (c) 2023 Nigerian Journal of Technological Development
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
In accordance with the Copyright Act of 1976, which became effective January 1, 1978, the following statement signed by each author must accompany the manuscript submitted: "I, the undersigned author, transfer all copyright ownership of the manuscript referenced above to the Nigerian Journal of Technological Development, in the event the work is published. I warrant that the article is original, does not infringe upon any copyright or other proprietary right of any third party, is not under consideration by another journal, and has not been published previously. I have reviewed and approve the submitted version of the manuscript and agree to its publication in the Nigerian Journal of Technological Development." A copyright transfer form should be downloaded from the NJTD Website ( http://njtd.com.ng/index.php/njtd). Author(s) will be consulted, whenever possible, regarding republication of material. All authors must have access to the data presented and the authors and sponsor (if applicable) must agree to share original data with the editor if requested.