Buoyancy effect study on convective enhancement for various base nanofluid in an enclosures

الملخص EN

Buoyancy-driven heat transfer convection enhancement in a two-dimensional enclosure, for two cases boundary conditions: (isothermal and linearly varying) temperature differential heated walls utilizing Nano fluid is studied numerically.

In this study, three various base fluids (water, ethylene glycol, or oil) based with (CuO) nanoparticles are tested.

Calculations of heat transfer rates were accomplished for a range of Rayleigh number (103 ≤Ra≤106 ), Prandtl number is taken as (Pr = 6.7, 204, and 10959), and solid volume fraction (0 % ≤ϕ≤ 10 %).

Numerical computations are carried out for different combinations of relevant parameters involved in the study.

Results showed that the heat transfer rate increases by increasing the volume fraction of the Nano fluid for all types of base Nano fluid considered.

The increment in average Nusselt number is strongly dependent on the basic fluid and boundary condition chosen.

The heat transfer rate also increases with increases of Rayleigh number, and Prandtl number.

Based on the present results, oil-base nanoparticle in an enclosure with the isothermal temperature walls is preferable to attain overall heat transfer enhancement.

Also, the enhancement in heat transfer with (0.1) solid volume fraction of (CuO) particles based with different basic fluids such as (water, EG, or oil) increases (26.7%, 28.8%, and 32.94%) respectively for low (Ra) as compared to the base fluid.

For verification of current study, the results have been compared with the recent studies at the same boundary conditions and are a good agreement.