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A numerical model for the simulation of aerosol flows via an Eulerian-Eulerian, one-way coupled, two-phase flow description is presented. An in-house computational fluid dynamics code is used to simulate the gaseous (continuous) phase, whereas a modified convective diffusion equation models particle transport. The convective diffusion equation, which includes inertial, gravitational, and diffusive particle transport, is solved by computational fluid dynamics techniques. The model is validated by comparing the calculated laminar fluid flow and particle deposition fractions to analytical and experimentally studied aerosol flows in a laminar flow 90• bend of circular cross section available in the literature. Model predictions are also compared with numerical predictions of Eulerian-Lagrangian models. Particle concentration profiles at different cross sections are calculated, and deposition sites on the wall boundary are indicated. For the range of studied particle diameters, the Eulerian-Eulerian model predicts deposition fractions satisfactorily, being in good agreement with the experimental data.

SUMMARYThe paper presents a numerical investigation of non-Newtonian modelling e ects on unsteady periodic ows in a two-dimensional (2D) channel with a stenosis. The geometry and boundary conditions were chosen so as to reproduce the ow features that are observed in real haemodynamic conditions. Three di erent 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 di erences 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.

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