On the significance of blood flow shear-rate-dependency in modeling of Fontan hemodynamics
| Autor: | Heng Wei, Niema M. Pahlevan, Andrew L. Cheng |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
business.industry
Quantitative Biology::Tissues and Organs Physics::Medical Physics Blood viscosity General Physics and Astronomy Hemodynamics 02 engineering and technology Mechanics Blood flow Computational fluid dynamics 01 natural sciences 010305 fluids & plasmas Physics::Fluid Dynamics Shear rate 020303 mechanical engineering & transports Circulation (fluid dynamics) 0203 mechanical engineering 0103 physical sciences Newtonian fluid Shear stress business Mathematical Physics Geology |
| Zdroj: | European Journal of Mechanics - B/Fluids. 84:1-14 |
| ISSN: | 0997-7546 |
| DOI: | 10.1016/j.euromechflu.2020.05.011 |
| Popis: | For univentricular heart patients, the Fontan operation creates a unique non-physiologic circulation where the pulmonary arteries are directly supplied from the systemic venous blood return, leading to chronic non-pulsatile low-shear-rate pulmonary blood flow. Computational fluid dynamic (CFD) simulations are widely used in cardiovascular biofluid studies and a Newtonian fluid assumption is common since blood acts as a Newtonian fluid in large arteries. Although blood viscosity increases exponentially in low-shear-rate flow environments, a Newtonian assumption is still conventionally used in both experimental and CFD studies of the low-shear-rate Fontan circulation. The error introduced by a Newtonian assumption in this setting has not been thoroughly evaluated. Recent in vitro studies have demonstrated that non-Newtonian effects are substantial in the Fontan circulation. However, no previous studies have used CFD to systemically investigate non-Newtonian effects in Fontan simulations. Thus the role of shear-rate-dependent non-Newtonian blood viscosity in this pathophysiology is still unclear. In this study we used a computational approach to compare flow behavior between a non-Newtonian fluid and a Newtonian fluid in a simplified model of the Fontan circulation over a wide range of experimental conditions. We examined important clinical metrics in Fontan hemodynamics: shear stress, power loss, pulmonary flow distribution, viscous dissipation, and non-Newtonian importance factors. Our results suggest that the Newtonian fluid assumption for blood introduces considerable error into the simulations of the Fontan circulation, where the fluid environment is predominated by low-shear-rate flow. |
| Databáze: | OpenAIRE |
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