Soret and Dufour Effects on Hydromagnetic Flow of H2O-Based Nanofluids Induced by an Exponentially Expanding Sheet Saturated in a Non-Darcian Porous Medium

Diffusion-thermo effect (Dufour effect) and thermal-diffusion effect (Soret effect) on an MHD flow through porous medium taking nanoparticles may be considered to be useful in many engineering problems when there is a species concentration along with the solid nanoparticles. To study such an attracting problem, it is necessary to consider the flow to be single-phase. In the present investigation, the hydromagnetic flow of H2O-based nanofluids due to an exponentially expanding sheet saturated in non-Darcian porous material is examined with Dufour and Soret effects. In addition, temperature and species concentration along the surface in flow distribution are considered to be variable exponentially. Two sorts of nanofluids are considered, to be specific, Cu–H2O and Ag–H2O. Use of proper similarity transformations transfers the governing PDEs to coupled ODEs. Then the solutions of the coupled equations are computed by very efficient shooting method. Non-dimensionless velocity species concentration and temperature are introduced in graphical mode for several values of involved parameters. Out of several obtained outcomes, it is noticeable that similar to the magnetic parameter and permeability parameter, due to increase in non-Darcy Forchheimer parameter velocity diminishes and while temperature and species concentration increments are witnessed. Due to presence of Dufour effect, temperature enhances and similarly, the concentration increases for Soret effect. While due to Dufour effect, the concentration initially decreases, but away from surface it increases and similar behaviour is found for temperature in the case of Soret effect. Also, it is obtained that skin-friction coefficient for Cu–H2O nanofluid is larger than it value for Ag–H2O nanofluid. Dufour effect turns into the reason for the reduction of Nusselt number and increment of Sherwood number for both nanofluids, but Soret effect affects the two nanofluids reversely. The analysis and its findings provide some tools which may be applied in engineering and industrial problems.

THE LID-DRIVEN HYDROMAGNETIC FLOW OF NEWTONIAN AND NON-NEWTONIAN LIQUIDS IN A SQUARE CAVITY

In this paper, we formulate the steady hydromagnetic lid-driven cavity problem in a stream function-vorticity form for weakly electrically conducting Newtonian and non-Newtonian liquids. Then we solve them by using the concept of pseudo time derivative. The classical benchmark results of the Newtonian liquid are recovered as a limiting case and the inhibiting influence of the magnetic field on the Newtonian and non-Newtonian liquids’ flow field is clearly depicted through graphs. We also show certain aspects of the flow for the first time in tables.

Gravity-driven hydromagnetic flow of couple stress hybrid nanofluid with homogenous-heterogeneous reactions

This investigation describes the hydromagnetic flow of gravity-driven couple stress hybrid nanofluid past a heated plate. The carbon nanotubes (CNTs) are used to characterize the hybrid nanofluid. The heated plate is placed vertically with an application of homogenous-heterogeneous reactions to the assumed flow system. The homogeneous reaction governs by isothermal cubic autocatalytic kinetics while the heterogeneous reaction governs by the first order kinetics. For current study the couple stress hybrid nanofluid is presumed to be conducted electrically with impact of non-uniform magnetic effects. An appropriate set of dimensionless quantities has employed to governing equations and then has solved by homotopy analysis method. The influence of emerging parameters encountered in this work has discussed in detail with the help of graphs. In this study it has examined that, flow of fluid reduces with upsurge in magnetic parameter and volumetric concentrations, whereas thermal and concentration characteristics augment with increase in volumetric concentrations. Moreover, growth in Prandtl number leads to a reduction in thermal characteristics and growth in Schmidt number result a reduction in concentration profile. The impact of various emerging parameters has also studied numerically upon physical quantities. It has established that, with augmentation in values of buoyancy parameter there is a growth in the values of skin friction. A comparison has also carried out between current and established results with a fine agreement in both results.

Hydromagnetic Flow Over a Heated Stretching Surface

In the present paper on steady flow of a viscous incompressible fluid past a heated stretching sheet with thermal radiation is studied. Magnetic field is applied normal to the flow. With suitable similarity transformations, the momentum and energy equations are reduced to ordinary differential equations. The governing differential equations with corresponding boundary conditions are solved numerically using MATLAB inbuilt solver bvp4c,. Graphical results for velocity and temperature fields, tabular values of Skin-friction and Nusselt numbers are presented and discussed. It is found the temperature of the fluid increases for the increasing values of radiation parameter.