ABSTRACT
This chapter focuses on the steady isothermal flow of a power-law fluid in the annular space between two long coaxial cylinders, with one of them in motion and/or an imposed pressure gradient. The theoretical analyses for these annular flow situations are complex for non-Newtonian fluids. The tangential flow of a power-law fluid through an annulus under only an imposed pressure gradient with both cylinders stationary is useful in the analysis of spiral molds. Helical flow involves the steady laminar motion of a fluid in an annulus, when one of two coaxial cylinders is rotated and an axial pressure gradient is simultaneously imposed. For a non-Newtonian fluid, it must be emphasized that the tangential and axial velocity components in helical flow are interdependent, making the flow analysis mathematically complicated. The inaccuracy is found to increase as fluids exhibit a higher degree of non-Newtonian behavior.
