Critical evaluation of three hemodynamic models for the numerical simulation of intra-stent flows

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. We evaluate here three hemodynamic models used for the numerical simulation of bare and stented artery flows. We focus on two flow features responsible for intra-stent restenosis: the wall shear stress and the re-circulation lengths around a stent. The studied models are the Poiseuille profile, the simplified pulsatile profile and the complete pulsatile profile based on the analysis of Womersley. The flow rate of blood in a human left coronary artery is considered to compute the velocity profiles. "Ansys Fluent 14.5" is used to solve the Navier-Stokes and continuity equations. As expected our results show that the Poiseuille profile is questionable to simulate the complex flow dynamics involved in intra-stent restenosis. Both pulsatile models give similar results close to the strut but diverge far from it. However, the computational time for the complete pulsatile model is five times that of the simplified pulsatile model. Considering the additional "cost" for the complete model, we recommend using the simplified pulsatile model for future intra-stent flow simulations.

Influence of the Recirculation Zones on the Mass Transfer for a DrugEluting Stent

“…This asymmetry results in the coupling between flow and mass transfer. As we have shown in another study [10], the convection stretches the distal cell and contracts the proximal cell. The mass transfer coupled to these flows therefore follows the same behavior.…”

Assessment of surface roughness and blood rheology on local coronary haemodynamics: a multi-scale computational fluid dynamics study

“…A simplified pulsatile model (equation (3.11)) has been used to describe the fully developed laminar flow occurring at the inlet as recommended by Chabi et al for modelling micro-scale features [ 68 ] (stents). where V ( t ) is the variation of velocity shown in figure 5 , r is the radial position and R is the maximum radius of the artery (adjusted for the increase in diameter due to the roughness).…”

“…1 modified Krieger model 5 parameters [54] (MKM5) The pulsatile variation of velocity over time, V(t), was applied to the inlet using a Fourier fitted series (R 2 = 0.998) based upon velocity data for the LAD [67]. A simplified pulsatile model (equation (3.11)) has been used to describe the fully developed laminar flow occurring at the inlet as recommended by Chabi et al for modelling micro-scale features [68]…”

Análisis de la Influencia de Un Stent con Diferente Sección Transversal en la Hemodinámica de la Arteria Coronaria Mediante Elemento Finito

“…Por otra parte, la simulación numérica se ha convertido en una herramienta importante para el diseño y estudio de problemas cardiacos [9][10][11][12]. En el presente trabajo se compara cualitativamente la influencia de un stent con diferentes formas en la sección transversal (strut).…”

“…Para la simulación se tomaron los siguientes valores de densidad: 1050 kg/m 3 , y de viscosidad dinámica: 3.46x10 -3 Pa s. La condición inicial del análisis transitorio es que el fluido no se mueve y que se encuentra a presión constante, presión venosa. La velocidad de entrada de la sangre se obtiene de las medidciones realizadas por [12]; que considera que un periodo en condiciones de reposo es de 0.8 s; y para la arteria coronaria se tiene una velocidad media de 0.16 m/s. Tomando esto en consideración, la función del tiempo que describe la condición de entrada es:…”