Analisis Aliran Darah Non-Newtonian Pseudoplastik di Arteri Ginjal pada Kasus Stenosis Arteri Renalis Menggunakan Model Carreau

Abstract

This study aims to analyze the behavior of blood flow as a non-Newtonian pseudoplastic fluid in renal arteries that experience stenosis with a degree of narrowing of 60% in various geometric shapes. The approach used in this study is a numerical simulation method based on Computational Fluid Dynamics (CFD) using COMSOL Multiphysics software, by combining the Navier-Stokes equation and the Carreau rheology model to represent the properties of blood flow whose viscosity depends on the shear rate. The geometry of the renal artery is built ideally by considering several stenosis scenarios: partial circumferential narrowing, narrowing around the diameter, and double stenosis. The simulation results show that stenosis with different shapes produces blood flow velocity distributions that vary significantly, even though they have the same degree of narrowing. Narrowing causes acceleration of blood flow in the stenosis area, increased wall stress, and changes in flow patterns in the arterial branches that can affect the distribution of perfusion to the kidneys. These findings show that in addition to the severity of stenosis, the geometric shape of the stenosis also has a major effect on flow dynamics and can be an important indicator in evaluating the clinical risk of kidney disease. The application of this mathematical model provides a more comprehensive understanding of hemodynamic phenomena and their relevance in a medical context.