Influence of Distal Stenosis on Blood Flow Through Coronary Serial Stenoses: A Numerical Study

2019 ◽  
Vol 16 (03) ◽  
pp. 1842003 ◽  
Author(s):  
Biyue Liu ◽  
Dalin Tang

Computer simulations of the blood flow through right coronary arteries with two stenoses in the same arterial segment are carried out to investigate the interactions of serial stenoses, especially the effect of the distal stenosis. Various mathematical models are developed by varying the location of the distal stenosis. The numerical results show that the variation of the distal stenosis has significant impact on coronary hemodynamics, such as the pressure drop, flow shifting, wall shear stress and flow separation. Our simulations demonstrate that the distal stenosis has insignificant effect on the disturbed flow pattern in the regions of upstream and across the proximal stenosis. In a curved artery segment with two moderate stenoses of the same size, the distal stenosis causes a larger pressure drop and a more disturbed flow field in the poststenotic region than the proximal stenosis does. A distal stenosis located at a further downstream position causes a larger pressure drop and a stronger reverse flow.

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mehdi Jahangiri ◽  
Mohsen Saghafian ◽  
Mahmood Reza Sadeghi

The turbulent pulsatile blood flow through stenosed arteries considering the elastic property of the wall is investigated numerically. During the numerical model validation both standardk-εmodel and RNGK-εmodel are used. Compared with the RNGK-εmodel, the standardK-εmodel shows better agreement with previous experimental results and is better able to show the reverse flow region. Also, compared with experimental data, the results show that, up to 70% stenosis, the flow is laminar and for 80% stenosis the flow becomes turbulent. Assuming laminar or turbulent flow and also rigid or elastic walls, the results are compared with each other. The investigation of time-averaged shear stress and the oscillatory shear index for 80% stenosis show that assuming laminar flow will cause more error than assuming a rigid wall. The results also show that, in turbulent flow compared with laminar flow, the importance of assuming a flexible artery wall is more than assuming a rigid artery wall.


2021 ◽  
Vol 1094 (1) ◽  
pp. 012120
Author(s):  
Hussein Togun ◽  
Ali Abdul Hussain ◽  
Saja Ahmed ◽  
Iman Abdul hussain ◽  
Huda Shaker

Author(s):  
Siti Aslina Hussain ◽  
Tan Hong Tat ◽  
Mohd Ismail Abdul Hamid ◽  
Norhafizah Abdullah ◽  
Azni Idris

2013 ◽  
Vol 17 (16) ◽  
pp. 1821-1834 ◽  
Author(s):  
Hamidreza Ghasemi Bahraseman ◽  
Kamran Hassani ◽  
Mahdi Navidbakhsh ◽  
Daniel M. Espino ◽  
Zahra Alizadeh Sani ◽  
...  

Author(s):  
D Nag ◽  
A Datta

In this paper, numerical results on steady laminar flow of blood through an artery having two successive identical axisymmetric restrictions are presented, at varying degrees of restrictions. Physically, such a flow has features in common with steady blood flow through an artery with multiple stenoses. Additionally, results are presented for the blood flow through an artery in the presence of a single restriction, for comparison. The artery has been modelled as a tube with a rigid wall. The rheological characteristics of blood have been assumed both as Newtonian and non-Newtonian. Three different non-Newtonian models of blood — power law, Quemada, and Carreau—Yasuda models — have been considered in the analysis. The haemodynamic effects of the restrictions on the axial velocity distribution, recirculation zones formed downstream to the restrictions, the wall shear stress, and the pressure drop in the artery have been analysed. The irreversible pressure loss coefficient is calculated from the pressure drop and its variation with the degree of stenosis is obtained.


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