Effect of Cu–Al2O3 nanocomposite coating on flow boiling performance of a microchannel

Convective heat transfer performance of Cu–Al2O3 nanocomposite coated surface has been investigated experimentally for its potential use in heat transfer equipment operating in corrosive environment. Experimental studies were carried out in a bottom surface heated single microchannel of 672 μm hydraulic diameter using de-ionized (DI) water as the coolant. Thin nanocomposite coating was developed on the bottom surface of the microchannel using electrocodeposition technique. Both single-phase and two-phase convective heat transfer experiments were performed at different mass flux. The results from microchannel with bare Cu surface are used as the baseline data. Cu–Al2O3 nanocomposite coating has been found to enhance single-phase heat transfer rate marginally, whereas in the two-phase regime, the enhancement was ∼30% to ∼120% depending on the flow rate and surface temperature with an additional pressure drop penalty of less than ∼15%. CHF also improves for the coated surface by ∼35% to ∼55%.