Computational analysis of left coronary bifurcating artery using different blood rheological models

Abstract

A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90° bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS and Casson model predicts low WSS at all inlet velocity conditions which is indifferent from other non-Newtonian models. In moderate and high flow rates all the models are indistinguishable except in low flow rate. In case of increasing flow rate, Carreau and Herschel-Bulkley model demonstrate decreasing the value of IG thus acting as Newtonian fluid except for Casson and non-Newtonian power law. In conclusion, Carreau and Herschel-Bulkley models can be used for bifurcating LCA rather than Casson and non-Newtonian power law as they are very much sensitive to the non-Newtonian behavior of blood. As Herschel-Bulkley model predicts lower IG values than the Carreau model thus Carreau is more appropriate as blood viscosity model for bifurcating LCA.A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90° bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS and Casson model predicts low WSS at all inlet velocity conditions which is indifferent from other non-Newtonian models. In moderate and high flow rates all the models are indistinguishable except in low flow rate. In c...