Dual solutions and stability analysis of a hybrid nanofluid over a stretching/shrinking sheet executing MHD flow

Abstract

In this paper, the unsteady magnetohydrodynamic (MHD) flow of hybrid nanofluid (HNF) composed of Cu-Al2O3/water in the presence of a thermal radiation effect over the stretching/shrinking sheet is investigated. Using similarity transformation, the governing partial differential equations (PDEs) are transformed into a system of ordinary differential equations (ODEs), which are then solved by using a shooting method. In order to validate the obtained numerical results, the comparison of the results with the published literature is made numerically as well as graphically and is found in good agreements. In addition, the effects of many emerging physical governing parameters on the profiles of velocity, temperature, skin friction coefficient, and heat transfer rate are demonstrated graphically and are elucidated theoretically. Based on the numerical results, dual solutions exist in a specific range of magnetic, suction, and unsteadiness parameters. It was also found that the values of f " (0) rise in the first solution and reduce in the second solution when the solid volume fraction ϕCu is increased. Finally, the temporal stability analysis of the solutions is conducted, and it is concluded that only the first solution is stable.