The micro/nanochannel cooling technology is a promising and flourishing technique of thermal management to dissipate the heat of electronic devices. Here, we apply fractal Cantor structures to construct the self-affine rough surface of the nanochannel and investigate the effect of the fractal Cantor surface on the convective heat transfer performance in nanochannels by using molecular dynamics simulation. We first find out that fractal structures can accelerate the temperature development of the fluid and improve the convective heat transfer of nanochannels in comparison with those of smooth surfaces. With the increase of the fractal number (n) and the surface wettability, both the heat transfer and flow resistance further increase. The largest comprehensive convective heat transfer performance indicator is obtained at n = 3. The results show that the expansion of low potential energy regions along with the increasing fractal number makes more near-wall fluid atoms gather at the wall-fluid interface to act as “phonon bridge” to promote the convective heat transfer in nanochannels. Meanwhile, the generation of narrowest gaps in the fractal structure of n = 3 induces the local hydrophobic effect, which can ameliorate comprehensive thermal and flow characteristics of nanochannels.

微/纳米通道冷却技术是一种有前途且蓬勃发展的热管理技术，可以消散电子设备的热量。在这里，我们应用分形Cantor结构构造纳米通道的自仿射粗糙表面，并使用分子动力学模拟研究分形Cantor表面对纳米通道中对流传热性能的影响。我们首先发现，与光滑表面相比，分形结构可以加速流体的温度发展并改善纳米通道的对流传热。随着分形数（n）和表面润湿性，传热和流动阻力都进一步增加。最大的对流传热综合性能指标在n  = 3时获得。结果表明，低势能区域的扩展以及分形数的增加使更多的近壁流体原子聚集在壁-流体界面上，从而充当“声子桥”以促进对流传热。同时，在n  = 3的分形结构中产生最窄的间隙会引起局部疏水效应，从而可以改善纳米通道的综合热和流动特性。