P.S. Datti

Diffusion of chemically reactive species of a non-Newtonian fluid immersed in a porous medium over a stretching sheet

Abstract The influence of reaction rate on the transfer of chemically reactive species in the laminar visco-elastic fluid flow immersed in a porous medium over a stretching sheet is considered. The flow is caused solely by the linearly stretching sheet and the reactive species is emitted from this sheet and undergoes an isothermal and homogeneous one-stage reaction as it diffuses into the surrounding fluid. A similarity transformation is introduced, which reduces the concentration conservation equation to an ordinary differential equation. An exact analytical solution due to Siddappa and Abel (Z. Angew. Math. Phys. 36 (1985) 890) is adopted for velocity, where as the concentration equation is obtained numerically for higher-order reactions. The numerical computations show that the effect of destructive chemical reaction is to reduce the thickness of concentration boundary layer and increase the mass transfer rate from the sheet to the surrounding fluid. This effect is more effective for zero- and first-order reaction than second- and third-order reactions.

Hydromagnetic Fluid Flow and Heat Transfer at a Stretching Sheet With Fluid-Particle Suspension and Variable Fluid Properties

In this paper, we investigate the influence of temperature-dependent fluid properties on the flow and heat transfer characteristics of an electrically conducting dusty fluid over a stretching sheet. Temperature-dependent fluid properties are assumed to vary as a function of the temperature. The governing coupled nonlinear partial differential equations along with the appropriate boundary conditions are transformed into coupled, nonlinear ordinary differential equations by a similarity transformation. The resultant coupled highly nonlinear ordinary differential equations are solved numerically by a second order implicit finite difference scheme known as the Keller–Box method. The numerical solutions are compared with the approximate analytical solutions, obtained by a perturbation technique. The analysis reveals that even in the presence of variable fluid properties the transverse velocity of the fluid is to decrease with an increase in the fluid-particle interaction parameter. This observation holds even in the presence of magnetic field. Furthermore, the effects of the physical parameters on the fluid velocity, the velocity of the dust particle, the density of the dust particle, the fluid temperature, the dust-phase temperature, the skin friction, and the wall-temperature gradient are assessed through tables and graphs.

Axisymmetric mixed convective MHD flow over a slender cylinder in the presence of chemically reaction

Abstract The present analysis is focused on the study of the magnetic effect on coupled heat and mass transfer by mixed convection boundary layer flow over a slender cylinder in the presence of a chemical reaction. The buoyancy effect due to thermal diffusion and species diffusion is investigated. Employing suitable similarity transformations, the governing equations are transformed into a system of coupled non-linear ordinary differential equations and are solved numerically via the implicit, iterative, second order finite difference method. The numerical results obtained are compared with the available results in the literature for some special cases and the results are found to be in excellent agreement. The velocity, temperature, and the concentration profiles are presented graphically and analyzed for several sets of the pertinent parameters. The pooled effect of the thermal and mass Grashof number is to enhance the velocity and is quite the opposite for temperature and the concentration fields.