Dual solutions of mixed convective hybrid nanofluid flow over a shrinking cylinder placed in a porous medium

Abstract

Mixed convective hybrid nanofluid flow over a shrinking cylinder saturated in a porous medium is analyzed in the presence of magnetic field. The mathematical model of the present problem is formulated with constant thermophysical properties. The system of governing equations is reduced to ordinary differential equations utilizing appropriate similarity transformations. The resulting equations are solved by the implicit Runge-Kutta-Butcher procedure together with Nachtsheim-Swigert iteration scheme. The key findings are that the skin friction coefficient and the Nusselt number are substantially augmented with the increase in mixed convection parameter, Ri, magnetic field parameter, M, and porosity parameter, K. However, the boundary layer separation is delayed owing to the higher value of M, Ri, K, curvature parameter, γ, volume fractions of Al2O3 (φ1) and Cu (φ2). Moreover, the thermal boundary layer for the Cu–Al2O3/H2O hybrid nanofluid is wider in comparison with that for Cu–H2O and Al2O3–H2O nanofluid. On the other hand, the momentum boundary layer is thicker for 10 % of Al2O3 nanoparticle volume fraction and the reverse is seen for 10 % volume fraction of Cu nanoparticle.