Analysis of Steady and Physiological Pulsatile Flow Characteristics in an Artery with Various Percentages of Restrictions

Abstract

Atherosclerosis, a progressive process, silently and slowly restricts the blood flow through artery. The flow characteristics of blood in the artery are important factors in the progression and formation of atherosclerosis. A numerical simulation has been carried out for analysis of steady and physiological pulsatile blood flow characteristics in a modeled artery for various percentage of restrictions in the lumen area of artery. The continuity and momentum equations have been solved by finite volume method considering blood as Newtonian fluid and stenosis as bell shaped in nature. The flow characteristics such as time averaged wall pressure, stream line contour and time averaged wall shear stress have been analyzed for different percentage of restriction and compared for both type of flows. The flow characteristics significantly vary with the percentage of restriction. The post-stenotic regions are occupied by the vortex rings for higher percentage of restriction. The maximum time averaged pressure drop and the peak time averaged wall shear stress are found to be located at the stenosis throat for all type of flows and restrictions. The study shows that steady flow characteristics are dominated by physiological pulsatile flow characteristics from the perspective of atherosclerosis. The time averaged wall pressure drop, the size of recirculation zone and the peak wall shear stress increase with increase in percentage of restriction. Thus chances of progression and formation of atherosclerosis increase with increase in percentage of restriction.