S. Kamangar - Department of Mechanical Engineering, College of Engineering, King Khalid University, PO Box ۳۹۴, Abha ۶۱۴۲۱, Kingdom of Saudi Arabia

This study explores the influence of tandem stenosis on hemodynamic constraints in idealized coronary artery models with different interspace distance between the stenosis and its severity. The blood was assumed as non-Newtonian, incompressible, and pulsatile fluid. The hemodynamic parameters of blood, such as the oscillatory shear index (OSI), wall shear stress (WSS) and time average wall shear stress (TAWSS) are obtained and compared for various degrees of stenosis and interspacing distance in various blood models. The computed results showed that as the interspacing distance between the stenosis decreases, the low wall shear stress area increases for the model P۷۰_D۷۰, leading to further progression of stenosis in the distal region. No significant variation was observed for the model P۷۰_D۹۰, whereas the low WSS region increases as the interspace distance of proximal and distal stenosis increases for the model P۹۰_D۷۰. The highest TAWSS sites were created across the ۹۰% AS (area stenosis) for all the cases studied. As the higher value of TAWSS is clinically significant since it could damage the endothelial layer. It is well known that the maximum value of OSI is strongly associated with the critical areas of stenosis rupture. The maximum value of OSI was found at the proximal and distal stenosis for all the models simulated.

wall shear stress, Computational fluid dynamics, non-Newtonian, Endothelial layer