Heat transfer enhancement in thermal systems has great importance in achieving better performances at decreased spaces. In the present work, by combining two passive enhancement methods of using miniaturized channels and utilizing nanofluid, the heat transfer from a heated surface is investigated. In this regard, the thermal performance of an Aluminum minichannel heat sink with rectangular cross-sections was experimentally investigated. The hydraulic diameter of the minichannels is 2 mm. Distilled water, TiO₂–water nanofluid, Al₂O₃-water nanofluid and hybrid Al₂O₃/TiO₂–water nanofluid were used with a volume fraction of 0.5% as coolants. Constant heat flux boundary condition was considered and maintained by a heater with the power of 36 W at the bottom of the heat sink. The effect of different Reynolds numbers ranged from 400 to 1000 on the thermal performance of the heat sink was evaluated. The experimental results indicated significant improvements in thermal characteristics by using nanofluids as a coolant instead of pure water. The convective heat transfer coefficient enhanced up to 16.97% compared to pure water. The wall temperature reduced up to 5 °C with using Al₂O₃/TiO₂–water hybrid nanofluid instead of pure water.

热系统中传热的增强对于在减小空间的情况下获得更好的性能非常重要。在目前的工作中，通过结合使用小型通道和利用纳米流体的两种被动增强方法，研究了从受热表面传热。在这方面，通过实验研究了具有矩形横截面的铝制微型通道散热器的热性能。微型通道的液压直径为2毫米。蒸馏水，TiO _2-水纳米流体，Al ₂ O _3-水纳米流体和混合Al ₂ O ₃ / TiO ₂–使用水纳米流体（体积分数为0.5％）作为冷却剂。考虑了恒定的热通量边界条件，并通过散热器底部的功率为36 W的加热器来维持该条件。评估了雷诺数从400到1000的不同值对散热器的热性能的影响。实验结果表明，通过使用纳米流体代替纯水作为冷却剂，可以显着改善热特性。与纯水相比，对流换热系数提高了16.97％。使用Al ₂ O ₃ / TiO _2-水混合纳米流体代替纯水，壁温降低至5°C 。