This study aims to investigate the effect of cavity inclination on thermosolutal mixed convection in a three-dimensional porous enclosure filled with a Cu–Al2O3/water hybrid nanoliquid. The objective is to evaluate the enhancement of mass and heat transmission performance compared to conventional nanofluids and pure water under different flow conditions, with particular emphasis on the effect of cavity inclination in aiding and opposing flow situations.
The three-dimensional porous container is differentially heated and concentrated, where the two vertical walls move in opposite directions at a constant velocity, while the remaining walls are fixed and adiabatic. The steady dimensionless governing equations are solved numerically using the finite volume method, and the porous structure is modeled using the Darcy–Brinkman–Forchheimer formulation. The analysis focuses on several governing parameters, including the buoyancy ratio, Darcy number, inclination angle, nanoparticle volume fraction, and Richardson number. The findings are presented in terms of the average Nusselt and Sherwood numbers as well as velocity profiles, while the isotherms, isoconcentration, and streamline contours are illustrated through both two-dimensional and three-dimensional representations.
The findings show that the hybrid nanofluid achieves better mass and heat transport performance compared to the single nanofluid. Furthermore, the effect of cavity inclination is shown to depend on the type of flow situation; for the aiding flow case (Br = 2), both Nuavg and Shavg increase with the inclination angle up to 30° for pure water and up to 45° for both types of nanofluids, beyond which a gradual reduction is observed, while the opposing flow case (Br = −2) exhibits the opposite trend. Moreover, the addition of nanoparticles to the clear water deteriorates heat transmission for particular Darcy and Richardson numbers, even yielding lower performance than pure water, due to the increase in viscosity outweighing the enhancement in thermal conductivity.
To the best of the authors’ knowledge and based on the available literature, no study has addressed thermosolutal mixed convection in an inclined three-dimensional porous enclosure using hybrid nanofluids with two-sided lid-driven boundary conditions. Therefore, the current work offers new and valuable insights into the combined effects of cavity inclination and hybrid nanoliquid on mass and heat transmission characteristics.
