Numerical analysis of Stefan blowing viscous fluid flowing above a stretching/shrinking disk

Abstract

AbstractAn incompressible, axi‐symmetric and magnetized viscous fluid flowing above a rotating disk is addressed. The disk can be stretch/shrink with a constant rate along the radial direction. The variable fluid features such as the viscosity, thermal conductivity and mass diffusion are considered in the flow governing equations. Two different cases of mass blowing/suction are considered. In the first case, the injection/suction is considered through the disk surface. The second case of injection/suction is through the surface of the disk by concentration gradient named as the Stefan effect. Similarity variables are accomplished to transform the governing system of partial differential equations into an ordinary one's. The resulting flow model is solved by bvp4c solver. The obtained physical parameters are discussed on velocity, thermal and concentration fields. For the better understanding of the flow phenomenon, the three‐dimensional flow visualization and its two‐dimensional contours against the physical parameters are sketched. The Nusselt and Sherwood numbers and skin‐friction against distinct constraints are calculated. It is observed that the suction parameter decreased the radial velocity curves for the stretching disk, while the velocity profiles are modified along radial direction in case shrinking disk against the increased suction parameter. The skin‐friction coefficient is enhanced for mass injection/suction and Stefan blowing/suction cases against the higher magnetic parameter values. The enhancement in variable thermal conductivity causes a reduction in local‐Nusselt number as well as the Sherwood number.