Numerical investigation of subcooled flow boiling of a nanofluid

Subcooled flow boiling of a nanofluid consisting of water and Al2O3 (dp = 30 nm) has been investigated numerically using two phase mixture model. Numerical predictions are compared to the previously published experimental works for pure water and alumina nanofluid and a good agreement is realized. It is observed that the convective heat transfer coefficient for a nanofluid in subcooled flow boiling is higher than that of the base fluid. Heat transfer coefficient increases with increasing of nanoparticles concentration. However, the effect of nanoparticle concentration on the heat transfer coefficient in the case of high inlet velocity is not significant. On the other hand, in subcooled flow boiling, decreasing the inlet mass flow rate can cause to decrease or increase the heat transfer coefficient which depends on the effect of forced convection and latent heat transport on the overall heat transfer coefficient. ► Subcooled flow boiling of a nanofluid is studied two phase mixture model. ► Convective heat transfer coefficient of nanofluid is higher than the base fluid. ► Different heat transfer mechanisms involves on the overall heat transfer coefficient. ► Increasing the inlet mass flow rate, heat transfer coefficient may increase or decrease.