Impact of turbulence modeling on the simulation of blood flow in aortic coarctation

Abstract

Numerical simulations of pulsatile blood flow in an aortic coarctation require the use of turbulence modeling. This paper considers three models from the class of large eddy simulation (LES) models (Smagorinsky, Vreman, σ-model) and one model from the class of variational multiscale models (residual-based) within a finite element framework. The influence of these models on the estimation of clinically relevant biomarkers used to assess the degree of severity of the pathological condition (pressure difference, secondary flow degree, normalized flow displacement, wall shear stress) is investigated in detail. The simulations show that most methods are consistent in terms of severity indicators such as pressure difference and stenotic velocity. Moreover, using second-order velocity finite elements, different turbulence models might lead to considerably different results concerning other clinically relevant quantities such as wall shear stresses. These differences may be attributed to differences in numerical dissipation introduced by the turbulence models.

Accurate and Efficient 3D Reconstruction of Right Heart Shape and Motion from Multi-Series Cine-MRI

“…The valves are modeled as surfaces immersed in the fluid dynamics domain managed by the Resistive Immersed Implicit Surface (RIIS) method (Fedele et al, 2017;Fernández et al, 2008;This et al, 2020a), accounting for the opening/closure of the two valves by means of an on-off modality and selecting a priori the opening/closure instants by the images (Fumagalli et al, 2020). Finally, to account for turbulence transition that may develop, we consider the Large Eddy Simulation σ model (Nicoud et al, 2011), which has been already extensively used in many hemodynamics applications (Katz et al, 2022;Stella et al, 2019;Vergara et al, 2017).…”

Selected aspects of blood flow simulations in arteries

“…The latter can be determined only using 2D or 3D models, preferably in time-dependent geometry. 2D models are applied to reduce computational time; in most cases, these papers assume axisymmetry of the geometry [6]. Both 2D and 3D models are based on solutions of the Navier-Stokes equations (mass and momentum conservation).…”