Following recent works of several authors like Huilgol, Bhattacharya etd. and
Javadpour et al., this paper is to contribute further to the literature of axial flow in a
rotational coaxial rheometer. We consider axial flow of Herschel Bulkley mode1
between two concentric cylinders with the inner one rotating, while the outer
cylinder is held stationary. An attempt has been made to direct the analysis toward
an examination of the relationship between moment (M) and angular velocity ( ) at
the inner cylinder. The radial dependence of the shear stress and viscosity follows
directly by our mathematical analysis with a simple numerical procedure. We
describe the relationship between shear stress and shear rate and the dependence of
these on axial flow rate in the annular region, for power law and Herschel Bulkley