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This article summaries a numerical study of thermo-solutal natural convection in a square cavity filled with anisotropic porous medium. The side walls of the cavity are maintained at constant temperatures and concentrations, whereas bottom wall is a function of non-uniform (sinusoidal) temperature and concentration. The non-Darcy Brinkmann model is considered. The governing equations are solved numerically by spectral element method using the vorticity-stream-function approach. The controlling parameters for present study are Darcy number (Da), heat source intensity i.e., thermal Rayleigh number (Ra), permeability ratio (K*), orientation angle (ϕ). The main attention is given to understand the impact of anisotropy parameters on average rates of heat transfer (bottom,Nub, sideNus) and mass transfer (bottom,Shb, side,Shs) as well as on streamlines, isotherms and iso-concentration. Numerical results show that, for irrespective value ofK*, the heat and mass transfer rates are negligible for 10−7≤Da≤ 10−5,Ra= 2 × 105andϕ= 45°. However a significant impact appears on Nusselt and Sherwood numbers whenDalies between 10−5to 10−4. The maximum bottom heat and mass transfer rates (Nub, Sub) is attained atϕ= 45°, whenK*=0.5 and 2.0. Furthermore, both heat and mass transfer rates increase on increasing Rayleigh number (Ra) for all the values ofK*. Overall, It is concluded from the above study that due to anisotropic permeability the flow dynamics becomes complex.

The present manuscript reports a numerical investigation of fully developed mixed convective flow in a parallel channel filled with porous medium. The motion in the channel is induced by external pressure gradient and buoyancy force. The non-Darcy Brinkman-Forchheimer extended model has been used. The Chebyshev spectral collocation method has been used to solve the coupled differential equations numerically. The main emphesize has been given on the influence of Forchheimer number (F), Darcy number (Da) and Rayleigh number (Ra) on velocity and temperature profiles. From this investegation we have found that the velocity as well as temperature profiles possess point of inflection beyond a threshold value of Ra. The back flow starts near the center of the channel on increasing the value of Ra beyond the threshold value of Ra. The point of inflection on the velocity as well as temperature profile dies out on decreasing of Da. The strength of the velocity is decreases on the increasing of F ′ , it also changes the velocity profile drastically. The point of inflection on the basic flow dies out on increasing of F ′ .

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