Non-Newtonian effects of blood on LDL transport inside the arterial lumen and across multi-layered arterial wall with and without stenosis

Abstract

Blood non-Newtonian behavior on low-density lipoproteins (LDL) accumulation is analyzed<br><br>numerically, while fluid-multilayered arteries are adopted for nonstenotic and 30%–60% symmetrical<br><br>stenosed models. Present model considers non-Newtonian effects inside the lumen and<br><br>within arterial layers simultaneously, which has not been examined in previous studies. Navier–<br><br>Stokes equations are solved along with the mass transport convection–diffusion equations and<br><br>Darcy's model for species transport inside the luminal flow and across wall layers, respectively.<br><br>Carreau model for the luminal flow and the modified Darcy equation for the power-law fluid<br><br>within arterial layers are employed to model blood rheological characteristics, appropriately.<br><br>Results indicate that in large arteries with relatively high Reynolds number Newtonian model<br><br>estimates LDL concentration patterns well enough, however, this model seriously incompetent<br><br>for regions with low WSS. Moreover, Newtonian model for plasma underestimates LDL concentration<br><br>especially on luminal surface and across arterial wall. Therefore, applying non-Newtonian<br><br>model seems essential for reaching to a more accurate estimation of LDL distribution<br><br>in the artery. Finally, blood °ow inside constricted arteries demonstrates that LDL concentration<br><br>patterns along the stenoses inside the luminal °ow and across arterial layers are strongly<br><br>in°uenced as compared to the nonstenotic arteries. Additionally, among four stenosis severity<br><br>grades, 40% stenosis is prone to more LDL accumulation along the post-stenotic regions.