Effect of rheological models on the hemodynamics within human aorta: CFD study on CT image-based geometry

Karimi, Safoora; Dabagh, Mahsa; Vasava, P.; Dadvar, Mitra; Dabir, Bahram; Jalali, Payman

doi:10.1016/j.jnnfm.2014.03.007

Cited by 97 publications

(49 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6 clearly demonstrates that the Newtonian predictions of WSS are consistently lower to those of the Casson model. This conclusion is in agreement with the predictions of Karimi et al (2014) for the WSS distribution in the human aorta. In addition, we notice that for the circumference of both cross-sections the maximum deviation between the WSS predictions of the two models occurs, in both cases, at the late-diastole time, t2 (Fig.…”

Section: Comparison Between the Newtonian And Casson Fluid Resultssupporting

confidence: 92%

“…Non-Newtonian models have been employed with increasing frequency for flow simulations of various vascular components, such as the aorta [Karimi et al (2014); Morbiducci et al (2013); Liu et al (2011)], the cerebral [Bernabeu et al (2013);Campo-Deaño et al (2015)], and the coronary arteries [Johnston et al (2006); Lassaline et al (2014); Chaichana et al (2012); Soulis et al (2008)]. In all of these cases, generalized Newtonian expressions are adopted which can better capture the complex behavior of the fluid under steady state conditions.…”

Section: Introductionmentioning

confidence: 99%

“…However, while there is strong evidence to support that the Casson model is the most suitable among constitutive equations for the description of blood flow faithfully, reproducing both its yield stress and shear thinning viscoplastic characteristics [Apostolidis and Beris (2014)], researchers often employ different models such as the Carreau-Yasuda [Lassaline et al (2014); Bernabeu et al (2013)] or a general power law [Chaichana et al (2012); Johnston et al (2006)]. The differences in the predictions of various rheological models are presented in a comparative study of Karimi et al (2014).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Non-Newtonian effects in simulations of coronary arterial blood flow

Apostolidis¹,

Moyer²,

Beris³

2016

Journal of Non-Newtonian Fluid Mechanics

View full text Add to dashboard Cite

We present a careful evaluation of non-Newtonian blood rheology effects in arterial flow simulations. We achieve that by comparing the converged solutions obtained a) from a Casson viscoplastic modeling of blood rheology using a recently developed parametrization [Apostolidis and Beris, J. Rheol., 58: 607-633 (2014)], and b) from a Newtonian model. We emphasize on the proper implementation of outlet boundary conditions (OBCs) in a way that ensures consistency with the pressure/flow predictions of the downstream network, which is modeled approximately using a 1D model [Johnson et al., Comp. Chem. Eng., 35: 1304-1316 (2011)]. We further improve and validate the iterative scheme proposed by [Johnson et al., Int. J. Num. Meth. Fluids, 66: 1383-1408 (2011)] for the implementation of the OBCs, by employing it in conjunction with a) Casson-derived simulation data, b) a more accurate geometrical model and c) an accelerated convergence iterative scheme through application of Shanks transformation. Finally, we performed a rigorous analysis to ensure appropriately converged solutions. Our investigation shows significant differences (up to 50%) between the simulation output of Newtonian and non-Newtonian models. The differences are attributed to the coupling that exists between low and high shear rate areas in the flow. They show the significance of non-Newtonian blood rheology and motivate further work towards an even more accurate modeling of the thixoropic and three-dimensional characteristics of the blood flow rheology that go beyond the Casson model utilized in the present work.

show abstract

Section: Comparison Between the Newtonian And Casson Fluid Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Non-Newtonian effects in simulations of coronary arterial blood flow

Apostolidis¹,

Moyer²,

Beris³

2016

Journal of Non-Newtonian Fluid Mechanics

View full text Add to dashboard Cite

show abstract

“…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: 55%

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

et al. 2015

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

“…with λ ¼ 3:313 s, n¼0.3568, μ 1 ¼ 3:45 Â 10 À 3 Pa s and μ 0 ¼ 0:56 Pa s. The BirdCarreau model with this set of parameters has been previously reported to perform well in simulations of arterial blood flows (Johnston et al, 2004;Soulis et al, 2008;Razavi et al, 2011;Karimi et al, 2014). The addition of drugs such as heparin or argatroban has been reported to reduce blood viscosity down to a 60% of its original value (Hitosugi et al, 2001).…”

Section: Model and Methodsmentioning

confidence: 90%