Unsteady boundary layer flow of nanofluid past a permeable stretching/shrinking sheet with convective heat transfer

This paper deals with the unsteady two-dimensional boundary layer flow and heat transfer of a nanofluid over a permeable stretching/shrinking sheet in the presence of heat generation/absorption. A convective heating boundary condition instead of a conventional prescribed temperature at the surface was employed to probe the variations of heat and concentration rates for different parameters including unsteadiness parameter, Brownian motion parameter, thermophoresis parameter and suction/injection. Results indicate that a dual solution exists for both stretching and shrinking sheets and that the unsteadiness and suction parameters may widen the ranges of stretching/shrinking parameter where the solution exists. Another noteworthy result is that the variational trend of heat transfer rate with unsteadiness parameter is opposite to the same trend of the prescribed temperature, which states the sensitivity of thermal boundary condition.