Mass-based attitude to single-phase hybrid nanofluid for a mixed assisting/opposing convective flow on vertical plate

In this article, we investigated the steady laminar MHD mixed convection stagnation-point flow of an alumina-Graphene/water hybrid nanofluid with spherical nanoparticles over a vertical permeable plate with focus on dual similarity solutions. The single-phase hybrid nanofluid modeling is based on nanoparticles and base fluid masses instead volume fraction of first and second nanoparticles as inputs. After substituting pertinent similarity variablesinto the basic PDEs governing on the problem, we obtain a complicated system of nondimensional ODEs, which has non-unique solution in a certain range of the buoyancy parameter. It is proved that the magnetic parameter and the wall permeability parameter widens the range of the buoyancy parameter for which the solution exists, however the opposite trend is valid for second nanoparticle mass. Besides, mass suction at the surface of the plate as well as magnetic parameter leads to reduce both hydrodynamic and thermal boundary layer thicknesses. Moreover, the assisting flow regime always has higher values of similarity skin friction and Nusselt number relative to opposing flow regime

Keywords:

Hybrid nanofluid , Dual solutions , Stagnation-point