Numerical solution of four different stenosis locations in bifurcated artery with heat transfer

Abstract

The development and progression of stenosis with a high probability of rupture can be characterised by changing the temperature distribution in the bifurcated artery. The purpose of this study is to investigate the behaviour of blood flow through four different locations of stenosis under the influence of heat transfer. In this study, the basic step of construction geometries (TYPE I, TYPE II, TYPE III, and TYPE IV that implies four possible morphologies formation of plaque from healthy to disease artery) are shown by using COMSOL Multiphysics 5.2. The blood flow is modelled as laminar, two-dimensional, steady, incompressible, and characterised as a Newtonian fluid. The classical Galerkin Weighted Residual (GWR) method is utilised to discretise the governing equations and boundary conditions. In addition, GWR is a convenient method to compute the solution since this method is compatible with circumventing the Babuska-Brezzi stability conditions. Firstly, a MATLAB source code is developed to solve the problem. Later, the results are compared with COMSOL Multiphysics 5.2 that based on the finite element method. The numerical validations are performed for the lid-driven cavity flow benchmark and the results of the axial velocity profile achieve a good agreement. This investigation focuses on the blood flow characteristics such as the velocity, temperature, pressure, streamline pattern, wall shear stress, and local Nusselt number, which have been discussed graphically and fundamentally. The parameters involved, such as Reynolds and Prandtl numbers, the maximum height of stenosis are very much affect the blood flow characteristics. Besides, TYPE IV shows the highest value of maximum velocity as compare to TYPE II and TYPE III. The backflow is formed in the post-stenotic region near the outer wall surface. Higher Reynolds number has enhanced the magnitudes of the wall shear stress predominantly in the downstream region of stenosis and reduced the pressure at the artery walls to some negative values resulted from the flow reversal. It shows that by increasing the maximum height of stenosis and Reynolds number, the shut of the peak for Nusselt number and also blood flow accelerations will increase rapidly.