Turbulent mixed convection of a nanofluid in a horizontal curved tube using a two-phase approach

Turbulent mixed convection heat transfer of a nanofluid consisting of water and Al2O3 (dp = 28 nm) throughout a horizontal curved tube has been investigated numerically. Two-phase mixture model has been implemented to study such a flow field. Elliptical governing equations have been solved to investigate the flow behaviors. Simultaneous effects of the buoyancy force, centrifugal force, and nanoparticles concentration have been presented and discussed. The computed results are compared with previously published experimental and numerical data for a base fluid (very low volume fraction, Φ ≈ 0, in the present simulation) and good agreement between the results is observed. It is seen that the nanoparticle volume fraction does not have a direct effect on the secondary flow and the skin friction coefficient. However its effects on the thermal parameters and flow turbulent intensity are significant.