Modeling of blood flow in the human aorta with use of an orthotropic nonlinear material model for the walls

We present a computational procedure and results for modeling of blood flow within the ascending human aorta, including all arterial branches and coronary arteries. We assume pulsatile blood flow and deformable walls. A 3D fluid domain is considered. The Arbitrary-Lagrangian-Eulerian (ALE) formulation and the implicit computational algorithm [1] for laminar viscous incompressible fluid flow is used. The blood walls are modeled by shell finite elements [2,3]- We introduce an orthotropic nonlinear material model, represented by a family of stress-stretch curves, to model the wall material behavior. The model is an extension of a uniaxial model [4]. We propose a computational procedure for the stress calculation for this material model. A loose coupling algorithm is used in solving the sohd-fluid interaction [5]. The described computational procedures are implemented in our FE program PAK [6].