Author(s)

A. Moura & C. Vergara

Abstract

The prescription of boundary conditions is a critical issue in 3D blood flow simulations. To account for the whole cardiovascular system, we can impose data measurements or couple the 3D model with reduced ones (see [4, 5, 9]). In either cases only average (mean pressure or flow rate) data are normally available, which must be properly fed to the Navier-Stokes solver. In this paper we propose an algorithm to impose mean flow rate boundary conditions in a problem posed on a compliant domain. It is an extension of the approach advocated in [3, 12]. Furthermore we consider the coupling between a 3D fluid-structure interaction model and a lumped parameters (0D) one, representing the systemic tree. We extend the two coupling techniques in [2, 11]. In the first approach the reduced model provides the mean pressure to be imposed as defective boundary condition to the 3D model, which converselywill make ready the flow rate to the reduced model. In the second strategy the type of data to be exchanged is reversed. 1 Introduction Blood flow simulations often require a detailed description of the flow in a specific sub-region of the cardiovascular system (e.g. carotid bifurcation, stenosed vessel, etc.). These detailed information is obtained by means of three-dimensional (3D) fluid-structure interaction models based on the coupling of the incompressible Navier-Stokes equations (when considering medium to large vessels) with a structure model for the vessel wall. A particular vascular district of interest is considered, thus specific data on the artificial boundary sections (i.e. the part of the

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