Title: Numerical simulation of viscoelastic blood flow with hematocrit variation in an arterial segment with two aneurysms
Authors: Ahmed Elhanafy; Ahmed Elsaid; Amr Guaily
Addresses: Mathematics and Engineering Physics Department, Faculty of Engineering, Mansoura University, Mansoura, 3551, Egypt ' Mathematics and Engineering Physics Department, Faculty of Engineering, Mansoura University, Mansoura, 3551, Egypt ' Engineering Mathematics and Physics Department, Faculty of Engineering, Cairo University, Giza, 12613, Egypt; Smart Engineering Systems Research Center (SESC), Nile University, Shaikh Zayed, 12588, Egypt
Abstract: In this study, a viscoelastic model with variable viscosity and relaxation-time is proposed for the simulation of the blood flow in an arterial segment with two aneurysms. The Quemada model is adopted to model both the shear rate-dependent viscosity and hematocrit variation. Available experimental data for the shear rate-dependent relaxation-time of the blood, in a certain range, are fitted and used. The arterial segment with aneurysms is considered as a rigid axisymmetric thin tube with two balloon expansions. The stabilised finite element method with the discrete elastic viscous stress splitting (DEVSS) method is used to solve the governing equations to overcome the numerical instabilities. Numerical results including velocity profiles, shear rate distribution and viscosity contours are obtained under different values of red blood cells (RBCs) concentrations. The results indicate that the hematocrit variation has a significant effect on the flow regimes and hemodynamics factors such as the wall shear stress (WSS). Hence, the shear thinning property should not be ignored for blood flow simulations.
Keywords: abdominal aortic aneurysms; AAAs; blood viscoelasticity; DEVSS method; hematocrit variation; wall shear stress; WSS.
Progress in Computational Fluid Dynamics, An International Journal, 2021 Vol.21 No.4, pp.222 - 233
Received: 19 Nov 2019
Accepted: 19 Jul 2020
Published online: 14 May 2021 *