Blood flow in the presence of a composite stenosis is investigated by examining the effects that red cell concentration, stenosis height and a peripheral layer have on blood flow characteristics. A two-layered model with a particle-fluid suspension in the core region and a peripheral plasma layer without any particles is used to represent blood. Expressions for three flow characteristics (impedance, wall shear stress and shear stress at the stenosis throat) are derived. Flow impedance increases with increasing hematocrit, stenosis height and diameter of the vessel but decreases with increasing tube length. The shear stress on the wall increases with increasing hematocrit, stenosis height and diameter of the vessel. Trends in the shear stress at the stenosis throat and impedance are similar with the variation of any parameter. The two-fluid model's flow characteristics are lower than those of the one-fluid model. In the analysis of the particle-fluid suspension the flow characteristics there were higher than when flow is considered to be particle-free. This knowledge of how the peripheral layer affects blood flow characteristics can aid in the understanding of diseased arterial systems

Blood flow through permeable microcirculation in the presence of a composite stenosis, an external magnetic field and convective heat transfer was examined. A two-layered model for the blood consisting of a fluid-particle suspension in the core region with a peripheral cell-free plasma layer was used. The proposed system of equations was solved and plots were generated. In the presence of permeable walls, an external magnetic field and convective heat transfer, the temperature of the blood, friction-factor Reynolds number and Nusselt number were investigated. The temperature of the blood increased when the Hartmann number increased, Darcy number increased, haematocrit level increased or the peripheral layer thinned. The friction-factor Reynolds number product increased as the haematocrit, Hartmann number, stenosis height or Darcy number increased. The Nusselt number decreased as the Hartmann number, haematocrit, stenosis height or Darcy number increased. These results were interpreted in terms of the physical situation. This study aids in understanding the effects of wall permeability, a magnetic field and the presence of heat transfer on different diseased arterial systems in the future.

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