Image-based large-eddy simulation in a realistic left heart

Chnafa, Christophe; Mendez, Simon; Nicoud, Franck

doi:10.1016/j.compfluid.2014.01.030

Cited by 151 publications

(237 citation statements)

References 68 publications

(88 reference statements)

Supporting

Mentioning

210

Contrasting

Order By: Relevance

“…This movement is hardly discernible in Fig. 5, because the vortical movement is mainly perpendicular to the cutting plane [3]. Two recirculation zones are however visible in Fig.…”

Section: Global Description Of the Cardiac Cyclementioning

confidence: 84%

“…A detailed flow description can be found in [3]; only the main flow characteristics are recalled here for the sake of completeness. Six salient instants are illustrated in Figure 5: the ventricular mid and end-systole (t/T =0.25-0.35), the beginning, peak and end of the E wave (t/T =0.45-0.55-0.65) and the end of the A wave, just before the beginning of the next ventricular systole (t/T =0.99).…”

Section: Global Description Of the Cardiac Cyclementioning

confidence: 99%

“…Here, an immersed boundary technique is used instead. A body force is imposed to drive the flow velocity to zero where the valves are located [3].…”

Section: Valvesmentioning

confidence: 99%

“…From visual inspection of the images, parameters as the average leaflets length, the orientation of the valve opening and an ellipse defining the opening area are imposed. Details of the procedure are described in Chnafa et al [3]. Knowing the MV leaflets position during the heart cycle, their effect on the blood flow is accounted for by using an immersed boundary method (IBM) [32].…”

Section: Valvesmentioning

confidence: 99%

See 3 more Smart Citations

Using Image-based CFD to Investigate the Intracardiac Turbulence

Chnafa¹,

Mendez²,

Moreno

et al. 2015

MS&A

View full text Add to dashboard Cite

A numerical framework designed to compute the blood flow in patientspecific human hearts is presented. The geometry of the heart cavities and associated wall motion are extracted from 4D medical images while the valves of the heart are accounted for thanks to low order geometrical models. The resulting blood flow equations are solved using a fourth-order low-dissipative finite-volume scheme and a mixed Aribtrary Lagrangian-Eulerian / Immersed Boundary framework. On top of retrieving the main fluid flow phenomena commonly observed in the left heart, the methodology allows studying the heart flow dynamics, including the turbulence characteristics and cycle-to-cycle variations.

show abstract

“…This movement is hardly discernible in Fig. 5, because the vortical movement is mainly perpendicular to the cutting plane [3]. Two recirculation zones are however visible in Fig.…”

Section: Global Description Of the Cardiac Cyclementioning

confidence: 84%

Section: Global Description Of the Cardiac Cyclementioning

confidence: 99%

“…Here, an immersed boundary technique is used instead. A body force is imposed to drive the flow velocity to zero where the valves are located [3].…”

Section: Valvesmentioning

confidence: 99%

Section: Valvesmentioning

confidence: 99%

See 2 more Smart Citations

Using Image-based CFD to Investigate the Intracardiac Turbulence

Chnafa¹,

Mendez²,

Moreno

et al. 2015

MS&A

View full text Add to dashboard Cite

show abstract

“…Numerical investigations of fluctuations in physiological flows have been dominated by the use of finite volume method 7 or spectral element methods 32 . Two recent computational studies demonstrate transitional flow in aneurysms 50;51 -these studies employed low-order finite elements but the scheme was tailored to minimize numerical dissipation in order to capture transition.…”

Section: Introductionmentioning

confidence: 99%

Transitional flow in intracranial aneurysms – A space and time refinement study below the Kolmogorov scales using Lattice Boltzmann Method

2016

View full text Add to dashboard Cite

Most Computational Fluid Dynamics (CFD) studies of hemodynamics in intracranial aneurysms are based on the assumption of laminar flow due to a relatively low (below 500) parent artery Reynolds number. A few studies have recently demonstrated the occurrence of transitional flow in aneurysms, but these studies employed special finite element schemes tailored to capture transitional nature of flow. In this study we investigate the occurrence of transition using a standard Lattice Boltzmann method (LBM). The LBM is used because of its computational efficiency, which in the present study allowed us to perform simulations at a higher resolution than has been done in the context of aneurysms before. The high space-time resolutions of 8 µm and 0.11 µs resulted in nearly 1 × 10 9 cells and 9 × 10 6 time steps per second and allowed us to quantify the turbulent kinetic energy at resolutions below the Kolmogorov scales. We perform an in-depth space and time refinement study on 2 aneurysms; one was previously reported laminar, while the other was reported transitional. Furthermore, we investigate the critical Reynolds number at which the flow transitions in aneurysms under time constant inflow conditions.

show abstract