  Of concern in the paper is a generalized theoretical study of the
non-Newtonian characteristics of peristaltic flow of blood through
micro-vessels, e.g. arterioles. The vessel is considered to be of variable
cross-section and blood to be a Herschel-Bulkley type of fluid. The progressive
wave front of the peristaltic flow is supposed sinusoidal/straight section
dominated (SSD) (expansion/contraction type); Reynolds number is considered to
be small with reference to blood flow in the micro-circulatory system. The
equations that govern the non-Newtonian peristaltic flow of blood are
considered to be non-linear. The objective of the study has been to examine the
effect of amplitude ratio, mean pressure gradient, yield stress and the power
law index on the velocity distribution, wall shear stress, streamline pattern
and trapping. It is observed that the numerical estimates for the aforesaid
quantities in the case of peristaltic transport of the blood in a channel are
much different from those for flow in an axisymmetric vessel of circular
cross-section. The study further shows that peristaltic pumping, flow velocity
and wall shear stress are significantly altered due to the non-uniformity of
the cross-sectional radius of blood vessels of the micro-circulatory system.
Moreover, the magnitude of the amplitude ratio and the value of the fluid index
are important parameters that affect the flow behaviour. Novel features of SSD
wave propagation that affect the flow behaviour of blood have also been
discussed.
