Helical flow of a power-law fluid in a thin annulus with permeable walls

Helical flow of a power-law fluid in a thin annulus is investigated with a view to modeling biofluid flow around the commonly occurring non-planar bend. The inner cylinder is rotating with angular velocity ωω and the outer cylinder is permeable. The velocity distribution and the fractional increase in volume flow rate are obtained. When the permeability parameter σ→∞σ→∞, the results agree with those of Bird et al. [Dynamics of polymer liquids, vol. 1, Fluid Mechanics, 1977, Wiley, New York]. Numerical methods are used to find the velocity components and the volume flow rate for the helical flow of a physiological fluid (power-law fluid). Possible advantages of the observed helical flow characteristics with permeability effects are discussed.