title: Large eddy simulations for blood dynamics in realistic stenotic carotids.
abstract: In this paper, we consider large eddy simulations (LES) for human stenotic carotids in presence of atheromasic plaque, a pathological condition where transitional effects to turbulence may occur, with relevant clinical implications such as plaque rupture. We provide a reference numerical solution obtained at high resolution without any subgrid scale model, to be used to assess the accuracy of LES simulations. In the context we are considering, ie, hemodynamics, we cannot refer to a statistically homogeneous, isotropic, and stationary turbulent regime; hence, the classical Kolmogorov theory cannot be used. For this reason, a mesh size and a time step are deemed fine enough if they allow to capture all the features of the velocity field in the shear layers developed after the bifurcation. To assess these requirements, we consider a simplified model of the evolution of a 2D shear layer, a relevant process in the formation of transitional effects in our case. Then, we compare the results of LES σ model (both static and dynamic) and mixed LES models (where also a similarity contribution is considered). In particular, we consider a realistic scenario of a human carotid, and we use the reference solution as gold standard. The results highlight the accuracy of the LES σ models, especially for the static model.
authors.affiliation: MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy.
authors.forename: Rocco Michele
authors.initials: RM
authors.lastname: Lancellotti
authors.affiliation: MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy.
authors.forename: Christian
authors.initials: C
authors.lastname: Vergara
authors.affiliation: MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Valdettaro
authors.affiliation: Institute for Computational and Mathematical Engineering (ICME), Stanford University, Stanford, CA, USA.
authors.forename: Sanjeeb
authors.initials: S
authors.lastname: Bose
authors.affiliation: SB SMA MATHICSE - CMCS, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Alfio
authors.initials: A
authors.lastname: Quarteroni
mesh_terms: D016893:Carotid Stenosis / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D014783:Viscosity
keywords: large eddy simulations; shear layer; stenotic carotids