The objective of the present study is to investigate the effect of nonlinear variation of density with temperature and concentration on the mixed convective flow of a micropolar fluid over an inclined flat plate in a non-Darcy porous medium in the presence of the convective boundary condition. In order to analyze all the essential features, the governing non-dimensional partial differential equations are transformed into a system of ordinary differential equations using a local non-similarity procedure and then the resulting boundary value problem is solved using a successive linearisation method (SLM). By insisting the comparison between vertical, horizontal and inclined plates, the physical quantities of the flow and its characteristics are exhibited graphically and quantitatively with various parameters. An increase in the micropolar parameter and non-Darcy parameter tend to increase the skin friction and the reverse change is observed in wall couple stress, mass and heat transfer rates. The influence of the nonlinear concentration parameter is more prominent on all the physical characteristics of the present model, compared with that of nonlinear temperature parameter.

The chemical reaction, Soret and Dufour effects on steady flow of a couple stress fluid between two rotating disks are studied. The lower disc is rotating with angular velocity Ω 1 where as the upper disc is rotating with Ω 2 . The density variation in centrifugal and Coriolis force terms are taken into consideration by invoking a linear density-temperature relation and Boussinesq approximation to account the buoyancy effects. The non-linear governing partial differential equations are transformed into system of ordinary differential equations by using the similarity transformations. Homotopy Analysis Method (HAM) has been used to solve the resulting equations. Graphical illustrations of the dimensionless velocity, concentration and temperature profiles are presented at different values of the emerging parameter of the present study. It has been found that as an increase in couple stresses leads to the decrease in velocity, temperature and increase in concentration of the fluid. Flow velocities, temperature and concentration profiles are decreases with an increase in reaction parameter.

The aim of the present paper is to study the influence of Hall current and Joule heating on flow, heat and mass transfer over an exponentially stretching sheet in a viscous fluid. Using similarity transformations the governing nonlinear coupled equations are converted into ordinary differential equations. These equations are linearized using the successive linearization method and then solved using the Chebyshev pseudo spectral method. The influence of magnetic parameter, Hall parameter, suction/injection parameter and slip parameter on the physical quantities are presented graphically. The obtained results are compared with the previously published results for special cases.