Abstract

Understanding blood flow hemodynamics and the fluid structure interaction (FSI) of blood with arterial walls is important for gaining insight into the fluid mechanics associated with many cardiovascular diseases. In this study, an image based model of the upper thoracic vasculature was created from MRI data using the Simpleware Software. The model was used to test and compare the FSI results predicted when three advanced multiphysics modeling methods; the Smooth Particle Hydrodynamics (SPH) Method, the Coupled Eulerian-Lagrangian (CEL) Method and the Lattice-Boltzmann Method (LBM) were used to simulate blood flow in the image based model of the vasculature. Each of the above methods, offers certain advantages in simulating complex FSI. The Lagrangian mesh free SPH method has been found to be useful in cases where there is a need to account for extremely high deformations where traditional methods often fail or are inefficient. When simulating FSI, the advantages of using the CEL method are large scale structural deformations, where the Volume-of-Fluids (VOF) method tracks material boundary in the Eulerian domain. CEL approach is an interaction between the Lagrangian bodies and the materials in the Eulerian mesh. The Eulerian technique is a complement to Lagrangian analysis and acceptable when extreme deformations cause the Lagrangian method to fail. The coupled Lattice-Boltzmann method, being particle-based method tackles many of the drawbacks presented by the traditional CFD methods such as mesh based solutions. In LBM approach, the meshing process is removed as the simulation relies on an automatically generated lattice which is organized in an Octree structure. All simulations were performed in the Abaqus and XFlow CFD software packages. This study assessed the performance and modeling capabilities of each of these methods by comparing the results of each method quantitatively for the predicted velocity field, the predicted wall shear stress and the global flow parameters.