Magneto-hydrodynamic double diffusion of non-Newtonian hybrid nanofluids in a wavy enclosure with Soret and Dufour effects

This article presents a numerical investigation of double-diffusive magnetohydrodynamic free convection in an inclined square enclosure with wavy horizontal walls, filled with Cu−Al2O3/water hybrid nanofluid. A uniform magnetic field is induced in the flow dynamics, and the flow further is influenced by Soret and Dufour effects. The left wall and a square block, placed at the center of the cavity, are maintained at higher temperature, while the right wall is kept cold; the horizontal walls are insulated. The study explores a wide range of key parameters, such as solid volume fraction (0 ≤ϕ≤ 0.1), Rayleigh number (103≤Ra≤106), power-law index (0.6 ≤n≤ 1.4), buoyancy ratio (−0.5 ≤Br≤ 1.0), and the angle of the lower walls of the enclosure concerning the x-axis (0°≤θ≤60°). The results show that the Soret and Dufour parameters enhance the heat and mass transfer rate. An analytical expression is also derived for the two-dimensional stream function considering the low aspect ratio cavity under certain presumptions and validated against numerical results for a low Prandtl number (Pr). The findings shows a significant impact of hybrid nanofluid and inclination angle of cavity on heat and mass transfer, offering insight for optimizing thermal performance in the design of box-shaped engine components.