Personalized numerical simulation of haemodynamics in abdominal aortic aneurysm: analysis of simulation sensitivity to the input boundary conditions
Ya.V. Fedotova1, R.Yu. Epifanov1, I.I. Volkova2, M.S. Maus2, N.A. Nikitin1,2, S.A. Aivazov2, M.Yu. Khrebtov3, A.A. Karpenko1,2, R.I. Mullyadzhanov1,3
1Novosibirsk State University, Novosibirsk, Russia
2Meshalkin National Medical Research Center, Novosibirsk, Russia
3Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: CFD simulation, personalized haemodynamics, abdominal aortic aneurysm, boundary conditions, Navier-Stokes equations
Abstract
The analysis was performed for input-condition sensitivity of haemodynamics simulation for the zone of abdominal aortic aneurysm. We took three versions of patient-specific configurations of aneurism and computed the haemodynamics with different spatial and velocity profiles at the inlet. Their impact on haemodynamic characteristics was evaluated. At total, the study was performed for three spatial variants (uniform, parabolic and parabolic-and-secondary-flow velocity profiles) and three versions of time behavior of velocity profiles: this produces nine cases for every of three chosen geometries. The study demonstrated that we can neglect the impact of spatial profile for inlet velocity (including the non-coaxial velocity vector components). Meanwhile, the value of reverse diastolic flow is significant for the solution. However, simulation in the zone of abdominal aortic aneurysm does not demonstrate great differences in simulation results for the values of wall shear stress and velocity for the data averaged over a cardiac cycle. For the distribution of the oscillation index of shear, the maximum deviation from the basic solution is about ~ 10 %, which is quite acceptable for clinical applications.
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