Magneto-nanofluid flow due to bidirectional stretching surface in a porous medium

The problem of unsteady nanofluid flow over a bidirectional stretched surface embedded in a porous medium with a magnetic field in the boundary layer region is studied. Brownian motion and thermophoresis characteristics are incorporated through a nanofluid model. The stretched surface is maintained at a prescribed temperature and nanoparticle concentration. The modeled governing equations are converted into dimensionless form using similarity transformations before finding the analytical and numerical solutions. Analytical treatment is made by employing the homotopy analysis method, while the Keller box method is employed for the numerical solution. The obtained solutions from both methods are compared and are found to be in good agreement. Comparisons are also made with previously published work and the outcomes are in decent agreement with previous results. The results for local Nusselt and Sherwood numbers against parametric values are described in the tables. Finally, temperature and concentration fields are discussed and analyzed through several plots. It is founded that the large values of the Brownian motion and thermophoresis parameters increase the width of the thermal and concentration boundary layer. © 2019 by Begell House, Inc.