Unsteady double-diffusive natural convection in a two-sided lid-driven inclined porous enclosure with sinusoidal boundary conditions with Soret and Dufour effects

Unsteady double-diffusive natural convection in an inclined porous enclosure with sinusoidal boundary conditions and Soret and Dufour parameters is studied. The unique aspects of the set-up are that the left vertical and bottom walls are heated and concentrated non-uniformly and uniformly, respectively, while the right vertical wall is well insulated and the top wall is maintained at a constant concentration and cold temperature. A staggered grid finite-difference method is used to solve the system of partial differential equations that model heat and mass transfer inside the enclosure. We demonstrate the effects of the Soret and Dufour parameters and the inclination angle on the unsteady double-diffusive natural convection in the inclined porous enclosure. With all the numerical studies, the least square curve fitting (exponential non-linear curve fitting) of average Nusselt number and average Sherwood number with respect to different Soret and Dufour numbers at the left vertical wall which is non-uniformly heated and concentrated is examined here. Comparison with previously published results shows an excellent agreement.     

Hydrothermal stagnation point flow of Carreau nanofluid over a moving thin needle with non-linear Navier's slip and cubic autocatalytic chemical reactions in Darcy-Forchheimer medium

The present analysis deals with the hydrothermal and stagnation point flow of non-Newtonian fluid characterized by Carreau model over a moving thin needle. Darcy-Forchheimer medium is introduced. Homogeneous and heterogeneous chemical reactions are involved in the flow model. Non-linear Navier's slip condition is taken into account. Buongiorno model is adopted. The present hydrothermal flow model is useful in many complex industrial processes. The required numerical solution is obtained by 4th order Runge Kutta method along with shooting technique. The some remarkable outcomes of the current study are that axial velocity whittles down with rise in Weissenberg number and exhibits reverse trend in response to increase in non-linear slip parameter. Amplification of homogeneous and heterogeneous reaction parameters leads to diminution of nanoparticles concentration. Surface viscous drag intensify due to increment in Forchheimer number and heat transfer rate ameliorates with hike in Weissenberg number for both power law behavior (shear thinning and shear thickening) of Carreau nanofluid.