Effects of blood models on flows through a stenosis

The paper presents a numerical investigation of non-Newtonian modelling effects on unsteady periodic flows in a two-dimensional (2D) channel with a stenosis. The geometry and boundary conditions were chosen so as to reproduce the flow features that are observed in real haemodynamic conditions. Three different non-Newtonian constitutive equations for modelling the shear characteristics of the blood namely the Casson, power-law and Quemada models, are utilized. Similarly with previous studies based on Newtonian modelling, the present simulations show the formation of several vortices downstream of the stenosis, as well as substantial variations of the wall shear stress throughout the unsteady cycle. Additionally, it is shown that: (i) there are substantial differences between the results obtained by Newtonian and non-Newtonian models, and (ii) the prediction of vortex formation, wall shear stress distribution and separation behind the stenosis is strongly dependent on the details of the non-Newtonian model employed in the simulations.