Non-Newtonian blood flow in human right coronary arteries: steady state simulations

Abstract

This study looks at pulsatile blood flow through four different right coronary arteries, which have been reconstructed from bi-plane angiograms. A non-Newtonian blood model (the Generalised Power Law), as well as the usual Newtonian model of blood viscosity, is used to study the wall shear stress in each of these arteries over the entire cardiac cycle. The difference between Newtonian and non-Newtonian blood models is also studied over the whole cardiac cycle using the recently generalised global non-Newtonian importance factor. In addition, the flow is studied by considering paths of massless particles introduced into the flow field.The study shows that, when studying the wall shear stress distribution for transient blood flow in arteries, the use of a Newtonian blood model is a reasonably good approximation. However, to study the flow within the artery in greater detail, a non-Newtonian model is more appropriate.

Flow instability and wall shear stress variation in intracranial aneurysms

“…'Carreau Yasuda 1' and 'Carreau Yasuda 2' refer to the CarreauYasuda model used in Cho & Kensey (1991) and Gijsen et al (1999b), respectively. 'Ballyk 1' and 'Ballyk 2' refer to the Ballyk model used in Johnston et al (2004) and Lee & Steinman (2007) Table 3. Non-Newtonian models and parameters used in the literature.…”

Optimizing drug delivery using non-uniform magnetic fields: a numerical study

“…Accordingly the flow profile becomes flattened compared to the parabolic profile arising for a constant viscosity. This flattening is most pronounced for low Reynolds numbers and a decrease in centerline velocity by over 10% for Reynolds numbers below 200 was obtained using the generalized power law (GPL) model of [2]. In order to be able to compare the effect on the capture of particles for various Reynolds numbers we used different particle sizes such that the quantity Mn p (evaluated using the average flow velocity and the field gradient at the centerline below the wire) was equal in all simulations.…”

Modeling of cell sorting and rare cell capture with microfabricated biodevices

“…The governing equations can be solved in both steady-state and dynamic cases. Due to the assumption of a Newtonian flow, the dynamic viscosity of the streaming fluid (e.g., blood) is treated as constant and can be defined as h = 0.0035 Pa s [24]. In spite of simplicity, one-phase Newtonian models can be used in such complex problems as the design (shape and size) and optimization of electrospray ionization mass spectrometry (MS) coupling using microfluidic devices [25].…”

“…However, in this instance, the Newtonian fluid assumption can be the origin of some inaccuracy. In MBDs, the typical convective velocity is 0.001 m/s [26]; however, application of complex viscosity models is advised at velocities up to 0.2 m/s [24]. Fortunately, different models, such as the Generalized Power law, the Walburn-Schneck, and the Carreau methods have been developed to describe the dynamic viscosity of streaming fluids as a function of the strain rate [24].…”

“…In MBDs, the typical convective velocity is 0.001 m/s [26]; however, application of complex viscosity models is advised at velocities up to 0.2 m/s [24]. Fortunately, different models, such as the Generalized Power law, the Walburn-Schneck, and the Carreau methods have been developed to describe the dynamic viscosity of streaming fluids as a function of the strain rate [24]. An innovative work was published in [12], where CFD simulations were used to determine the decrease of blood viscosity in the microchannels due to the Fahraeus effect, that is, when blood flows through a small diameter microchannel, the average hematocrit (solid particles of blood) in the microchannel is smaller than that in the reservoir so that blood viscosity decreases within the microchannel).…”