Non-Newtonian Arterial Blood Flow through an Overlapping Stenosis

The effects of an overlapping stenosis on blood flow characteristics in a narrow artery have been investigated. To account for the non-Newtonian behavior, blood has been represented by a Casson fluid. The equation describing the flow has been solved and the expressions for the flow characteristics, namely, the impedance, the wall shear stress, the shear stress at the stenosis throats and the shear stress at the critical height of the stenosis have been derived. It is shown that the impedance increases with the non-Newtonian behavior of blood as well as with the stenosis size. The shear stress at the stenosis two throats assumes the same magnitude. The shear stress at the stenosis critical height assumes significantly lower magnitude than its corresponding value at the throats. With respect to any given parameter, the nature of the variations of shear stresses at the throats and at the critical height of the stenosis is similar to that of the flow resistance.