Variation of the recirculation length of Newtonian and non-Newtonian power-law fluids in laminar flow through a suddenly expanded axisymmetric geometry

A numerical study has been carried out for the laminar flow of Newtonian and non-Newtonian power-law fluids through a suddenly: expanded axisymmetric geometry. Mathematical correlations are proposed for the prediction of the length of the recirculating eddy in terms of Reynolds number expansion ratio and rheological parameters. A wide range of expansion ratios (1.25 <= ER <= 8.0) has been covered for the Newtonian fluid and both the shear-thinning and shear-thickening flow characteristic fluids have been considered for the non-Newtonian fluids.