Numerical study flow and natural convection heat transfer affected by solid wall conduction in cavity filled nano fluid

In this article, the authors investigate free convection heat transfer in a cavity containing water-copper nanofluid affected by solid wall conduction using numerical methods. The governing equations were solved using a dimensionless numerical method and a simple algorithm. The authors investigated the effect of important parameters, including the volume fraction of nanoparticles and the ratio of the thermal conductivity coefficient of the solid region to the nanofluid, on the flow and heat transfer of the free movement of the chamber. The investigations were carried out at Rayleigh number Ra = 105, volume fractions ϕ=0, ϕ=0.02 and ϕ=0.05 for the ratio of thermal conductivity coefficients Kr =0.1, Kr =1 and Kr =10. The results showed that with an increase in the volume fraction of nanoparticles and the ratio of the conduction coefficient, the speed and power of the flow increased on average. Additionally, an increase in the volume fraction of nanoparticles and the ratio of the conductivity coefficient led to a decrease in the dimensionless temperature of the nanofluid. Moreover, compared to the case of Kr = 1, increasing the volume fraction of nanoparticles and the values of the ratio of the conduction coefficient led to higher Nusselt values along the walls, indicating a higher heat transfer rate passing through the interface of solid and nanofluid. Therefore, a higher ratio of the conduction coefficient can be useful for cooling and reducing the overall temperature of the cavity