Numerical Investigations on the Advantage of Nanofluids under DDMC in a Lid‐Driven Cavity

Double diffusive mixed convection in a lid‐driven cavity filled with Cu–water nanofluid is studied in detail. Various numerical experiments are conducted under horizontal thermal and concentration gradients. Flow equations were solved in velocity vorticity form using Galerkin's weighted residual finite element method. The Maxwell‐Garnett model and Brinkman models are applied to predict the thermal conductivity and dynamic viscosity of the nanofluid, respectively. The effectiveness of a nanofluid on heat transfer enhancement with respect to change in Richardson number has been studied at different Reynolds numbers for variation in particle volume fraction from 0 to 0.05. Similarly, the effect of buoyancy ratio on heat and mass transfer is presented for buoyancy ratio in the range of ?25 to 25. Detailed contour plots comparing the streamlines, temperature, concentration with and without nanoparticles were presented for all the range of parameters considered. The role of particle concentration and change in type of nanofluid has been reported. The average Nusselt number has increased in all the cases where as the Sherwood number slightly decreased with an increase in particle volume fraction. The Ag–water nanofluid showed better improvement in heat transfer characteristics compared to other nanofluids for all Reynolds numbers and particle volume fractions.