Wall shear stress variations and unsteadiness of pulsatile blood-like flows in 90-degree bifurcations

Wyk, Stevin van; Wittberg, Lisa Prahl; Fuchs, László

doi:10.1016/j.compbiomed.2013.05.008

Cited by 23 publications

(19 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, neglecting the non-Newtonian effects that blood exhibits leads to significant differences in the flow field and in WSS. 20 This conclusion is also supported by Karimi et al, 31 who showed that at peak systole, there is a clear effect of blood rheology on wall shear stress, especially in the brachiocephalic and carotid branches. In this work, we are investigating the flow structures developing in a 180 • bend, both through experiments and numerical simulations.…”

Section: Introductionsupporting

confidence: 64%

“…In a previous study, we demonstrate the importance of the non-Newtonian aspects. 20,46 Thus, a non-Newtonian viscosity model is implemented to account for the local variation in shear rate (γ), i.e., accounting for the shear-thinning behavior.…”

Section: A Fluid Modelsmentioning

confidence: 99%

“…However, the time history of the development of flow structures directly governs the near-wall flow behavior and thus, the WSS and its temporal and spatial derivatives. 20 Except the influence of the pulsating flow characterizing physiological flows, blood rheology is important to correctly capture the dynamics of the flow where different empirical formulas have been presented in the literature to capture the non-linear viscosity of blood. 20 Blood as a fluid has shear-thinning and viscoelastic non-Newtonian characteristics.…”

Section: Introductionmentioning

confidence: 99%

“…20 Except the influence of the pulsating flow characterizing physiological flows, blood rheology is important to correctly capture the dynamics of the flow where different empirical formulas have been presented in the literature to capture the non-linear viscosity of blood. 20 Blood as a fluid has shear-thinning and viscoelastic non-Newtonian characteristics. In small diameter vessels (e.g., capillaries and arterioles), blood can be assumed to be non-Newtonian due to the agglomeration of columns of red blood cells to form coherent elastic structures in such vessels.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Non-Newtonian perspectives on pulsatile blood-analog flows in a 180° curved artery model

et al. 2015

Self Cite

View full text Add to dashboard Cite

Complex, unsteady fluid flow phenomena in the arteries arise due to the pulsations of the heart that intermittently pumps the blood to the extremities of the body. The many different flow waveform variations observed throughout the arterial network are a result of this process and a function of the vessel properties. Large scale secondary flow structures are generated throughout the aortic arch and larger branches of the arteries. An experimental 180° curved artery test section with physiological inflow conditions was used to validate the computational methods implemented in this study. Good agreement of the secondary flow structures is obtained between experimental and numerical studies of a Newtonian blood-analog fluid under steady-state and pulsatile, carotid artery flow rate waveforms. Multiple vortical structures, some of opposite rotational sense to Dean vortices, similar to Lyne-type vortices, were observed to form during the systolic portion of the pulse. Computational tools were used to assess the effect of blood-analog fluid rheology (i.e., Newtonian versus non-Newtonian). It is demonstrated that non-Newtonian, blood-analog fluid rheology results in shear layer instabilities that alter the formation of vortical structures during the systolic deceleration and onwards during diastole. Additional vortices not observed in the Newtonian cases appear at the inside and outside of the bend at various times during the pulsation. The influence of blood-analog shear-thinning viscosity decreases mean pressure losses in contrast to the Newtonian blood analog fluid.

show abstract

Section: Introductionsupporting

confidence: 64%

Section: A Fluid Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Non-Newtonian perspectives on pulsatile blood-analog flows in a 180° curved artery model

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…There exist several models for blood viscosity dependence on α and the shear rate, γ [19]. In the following, the Quemada model is used [20].…”

Section: Rheological Modelmentioning

confidence: 99%

Stenosis Indicators Applied to Patient-Specific Renal Arteries without and with Stenosis

Fuchs

Berg

Wittberg

2019

Fluids

Self Cite

View full text Add to dashboard Cite

Pulsatile flow in the abdominal aorta and the renal arteries of three patients was studied numerically. Two of the patients had renal artery stenosis. The aim of the study was to assess the use of four types of indicators for determining the risk of new stenosis after revascularization of the affected arteries. The four indicators considered include the time averaged wall shear stress (TAWSS), the oscillatory shear index (OSI), the relative reference time (RRT) and a power law model based in platelet activation modeling but applied to the endothelium, named endothelium activation indicator (EAI). The results show that the indicators can detect the existing stenosis but are less successful in the revascularized cases. The TAWSS and, more clearly, the EAI approach seem to be better in predicting the risk for stenosis relapse at the original location and close to the post-stenotic dilatation. The shortcomings of the respective indicators are discussed along with potential improvements to endothelial activation modeling and its use as an indicator for risks of restenosis.

show abstract

Hemodynamics

Gasser

2021

Vascular Biomechanics

View full text Add to dashboard Cite

Wall shear stress variations and unsteadiness of pulsatile blood-like flows in 90-degree bifurcations

Cited by 23 publications

References 45 publications

Non-Newtonian perspectives on pulsatile blood-analog flows in a 180° curved artery model

Non-Newtonian perspectives on pulsatile blood-analog flows in a 180° curved artery model

Stenosis Indicators Applied to Patient-Specific Renal Arteries without and with Stenosis

Hemodynamics

Contact Info

Product

Resources

About