Unsteady double-diffusive convection in a water-based Al₂O₃-nanofluid in a two-sided lid-driven porous cavity

ABSTRACT

A numerical investigation of the flow and behaviour of properties of a water-based Al₂O₃-nanofluid inside a two-sided lid-driven inclined non-uniformly heated and concentrated porous cavity is made in this paper. The focus of the study is on determining how the buoyancy ratio and the inclination angles influence the unsteady double-diffusive natural convection in a cavity filled with a porous medium, and with non-uniform boundary conditions. We further consider different nanoparticle volume fractions of the nanofluid. It is assumed that the left and right vertical walls are insulated, while the bottom wall is heated and concentrated non-uniformly and the top wall maintained at a constant cold temperature. The top and bottom walls move from left to right and right to left with constant speed, respectively. The governing equations are solved numerically using a staggered grid finite-difference method for streamlines, isotherms, iso-concentrations, average Nusselt number and average Sherwood number for various values of nanoparticle volume fraction, inclination angle and buoyancy ratio. The change in the flow, temperature and concentration profile patterns with respect to time is depicted and described. The results are compared with previously published work and excellent agreement has been obtained.

KEYWORDS:

• Al₂O₃-nanofluid
• double-diffusive convection
• inclined lid-driven cavity
• buoyancy ratio

Disclosure statement

No potential conflict of interest was reported by the authors.