... by homotopy analysis method. The variation of dimensionless velocities are sketched in order to see the influence of pertinent parameters. Skin friction coefficient and wall couple stress coefficient have been tabulated. In addition, the derived results are compared with the homotopy perturbation solution...

...Nam-Sub Woo; Young-Ju Kim; Young-Kyu Hwang This experimental study concerns the characteristics of vortex flow in a concentric annulus with a diameter ratio of 0.52, whose outer cylinder is stationary and inner one is rotating. Pressure losses and skin friction coefficients have been measured...