Numerical considerations for advection-diffusion problems in cardiovascular hemodynamics

摘要

Numerical simulations of cardiovascular mass transport pose significant challenges due to the wide range of Peclet numbers and backflow at Neumann boundaries. In this paper we present and discuss several numerical tools to address these challenges in the context of a stabilized finite element computational framework. To overcome numerical instabilities when backflow occurs at Neumann boundaries, we propose an approach based on the prescription of the total flux. In addition, we introduce a "consistent flux" outflow boundary condition and demonstrate its superior performance over the traditional zero diffusive flux boundary condition. Lastly, we discuss discontinuity capturing (DC) stabilization techniques to address the well-known oscillatory behavior of the solution near the concentration front in advection-dominated flows. We present numerical examples in both idealized and patient-specific geometries to demonstrate the efficacy of the proposed procedures. The three contributions discussed in this paper successfully address commonly found challenges when simulating mass transport processes in cardiovascular flows. Novelty Statement The presented study is to the best of our knowledge the first implementation of backflow stabilization for 3D scalar mass transport problems. In addition, this paper is the first analysis of the "consistent flux" boundary condition in 3D patient-specific geometries. The novelty of our study is the implementation of backflow stabilization, the consistent flux boundary condition, and discontinuitycapturing stabilization in a unified scalar mass transport framework that can be applied to study the cardiovascular system.