Two-layered model of Casson fluid flow through stenotic blood vessels: applications to the cardiovascular system.

The effects of peripheral layer viscosity on physiological characteristics of blood flow through the artery with mild stenosis have been investigated. Blood has been represented by a two-fluid model, consisting of a core region of suspension of all the erythrocytes assumed to be a Casson fluid and a peripheral layer of plasma as a Newtonian fluid. The study is based on theoretical considerations and numerical evaluations and is restricted to the flow of blood through small arteries (130-1000 microns in diameter). It has been found that the resistance to flow and the wall shear stress decrease as the peripheral layer viscosity decreases. These characteristics are found to be decreasing as peripheral layer thickness increases. The numerical results show that the existence of the peripheral layer is helpful in functioning of the diseased arterial system. The analysis has been applied to calculate the resistance to flow and wall shear stress in different blood vessels.