Boundary layer

Physics

Pure mathematics

Mathematics

Matrix similarity

Heat transfer

Mechanics

Partial differential equation

Schmidt number

Mathematical analysis

Homotopy analysis method

Boundary layer thickness

Boundary value problem

Dimensionless quantity

Materials science

Nanofluid

Flow (mathematics)

Mass transfer

Differential equation

Ordinary differential equation

Homotopy

Prandtl number

Thermal radiation

Thermodynamics

Journal of Applied Mathematics

In this paper, analytic approximation to the heat and mass transfer characteristics of a two-dimensional time-dependent flow of Williamson nanofluids over a permeable stretching sheet embedded in a porous medium has been presented by considering the effects of magnetic field, thermal radiation, and chemical reaction. The governing partial differential equations along with the boundary conditions were reduced to dimensionless forms by using suitable similarity transformation. The resulting system of ordinary differential equations with the corresponding boundary conditions was solved via the homotopy analysis method. The results of the study show that velocity, temperature, and concentration boundary layer thicknesses generally decrease as we move away from the surface of the stretching sheet and the Williamson parameter was found to retard the velocity but it enhances the temperature and concentration profiles near the surface. It was also found that increasing magnetic field strength, thermal radiation, or rate of chemical reaction speeds up the mass transfer but slows down the heat transfer rates in the boundary layer. The results of this study were compared with some previously published works under some restrictions, and they are found in excellent agreement.

Heat and Mass Transfer in Unsteady Boundary Layer Flow of Williamson Nanofluids