Numerical study on variation of feedback methods in ultrasonic-measurement-integrated simulation of blood flow in the aneurysmal aorta

The complicated relationships between hemodynamics and aneurysms have been investigated intensively. However, existing methodologies have inherent limitations in providing real blood flow fields. The authors have proposed Ultrasonic-Measurement-Integrated (UMI) simulation, in which the feedback signals lead to convergence of the calculated blood flow structure to the real one even with incorrect boundary/initial conditions. In UMI simulation, determination of the feedback law is substantially important, but detailed particulars remain to be accounted for. In this paper, first, the effects of density of feedback points and feedback domains are systematically investigated. Improvement of computational accuracy in the feedback domain is achieved even in low density of feedback points of 25%, and such improvement persists in the downstream region. Secondly, the most effective combination of feedback gains for momentum and pressure equations is investigated, confirming the validity of the simple condition to use the same value for the velocity and pressure gains.