Effect of Mixing Ratio on the Flow and Heat Transfer Characteristics of Hybrid Nanofluids in Microchannels

Al2O3 and TiO2 nanofluids based on DI-water with different maxing ratio were prepared by the two-step methods, and the total volume concentration is 0.2%, respectively. A thermal property analyzer (Hot-Disk 2500S) was used to measure the thermal conductivity of hybrid nanofluids. The prepared hybrid nanofluids were used to flow through microchannel heat sinks to test the flow and convective heat transfer characteristics. The hydraulic diameters of microchannels are 104.35 µm, and the shapes of the channels are straight-line and broken-line. The experiment results show that, compared with DI-water, the heat transfer performance of nanofluids is better. Compared with DI-water, the convective heat transfer coefficients of the Al2O3 and TiO2hybrid nanofluids with maxing ratio 1: 1 in the broken-line microchannel are increased by 9.0% in Re=305. © 2020, Science Press. All right reserved.