Numerical investigation of abdominal aortic aneurysm hemodynamics using the reduced unified continuum formulation for vascular fluid-structure interaction

TL;DR

This study introduces a computationally efficient fluid-structure interaction model for abdominal aortic aneurysm hemodynamics, utilizing a reduced unified continuum formulation with advanced numerical methods for accurate, patient-specific simulations.

Contribution

The paper develops a reduced unified continuum FSI formulation with improved temporal accuracy and solver efficiency, applied to patient-specific aneurysm modeling.

Findings

Varying wall properties significantly affect hemodynamics.

The model achieves second-order temporal accuracy.

Efficient solver strategies improve computational performance.

Abstract

We recently demonstrated the reduction of the unified continuum and variational multiscale formulation to a computationally efficient fluid-structure interaction (FSI) formulation via three sound modeling assumptions pertaining to the vascular wall. Similar to the coupled momentum method introduced by Figueroa et al., the resulting semi-discrete formulation yields a monolithically coupled FSI system posed in an Eulerian frame of reference with only a minor modification of the fluid boundary integral. To achieve uniform second-order temporal accuracy and user-controlled high-frequency algorithmic damping, we adopt the generalized-$\alpha$ method for uniform temporal discretization of the entire coupled system. In conjunction with a fully consistent, segregated predictor multi-corrector algorithm preserving the block structure of the incompressible Navier-Stokes equations in the implicit solver's associated linear system, a three-level nested block preconditioner is adopted for improved representation of the Schur complement. In this work, we apply our reduced unified continuum formulation to an appropriately prestressed patient-specific abdominal aortic aneurysm and investigate the effects of varying spatial distributions of wall properties on hemodynamic and vascular wall quantities of interest.