Proposition of an outflow boundary approach for carotid artery stenosis CFD simulation

Abstract

The purpose of this study was to propose an innovative approach of setting outlet boundary conditions for the computational fluid dynamics (CFD) simulation of human common carotid arteries (CCAs) bifurcation based on the concept of energy loss minimisation at flow bifurcation. Comparisons between this new approach and previously reported boundary conditions were also made. The results showed that CFD simulation based on the proposed boundary conditions gave an accurate prediction of the critical stenosis ratio of carotid arteries (at around 65%). Other boundary conditions, such as the constant external pressure (P = 0) and constant outflow ratio, either overestimated or underestimated the critical stenosis ratio of carotid arteries. The patient-specific simulation results furthermore indicated that the calculated internal carotid artery flow ratio at CCA bifurcation (61%) coincided with the result obtained by clinical measurements through the use of Colour Doppler ultrasound.

Keywords::

• carotid artery stenosis
• cerebralvascular flows
• computational fluid dynamics
• energy loss

Acknowledgements

This study was partially supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT); grant number A22591599, and Australian Research Council Linkage Grant; grant number LP0990263, C.I.: Y. Qian. We are also thankful to Mr Keith Ng for his contribution to this manuscript.