Xiao Chengdi, Yu Dalin, Huang Jiaxun, Zhang Haitao, Rao Xixin
School of Advanced Manufacturing, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
J Mol Model. 2025 May 27;31(6):171. doi: 10.1007/s00894-025-06389-6.
Ongoing advancements in microelectronic device integration and performance have intensified thermal management challenges. Surface roughness and wettability are key parameters for bubble nucleation during flow boiling, yet their nano-scale effects are not fully understood. This study uses molecular dynamics simulations to explore how wetted micro/nano-structured surfaces affect flow boiling, focusing on roughness, alignment, and driving forces. Results show that applying a force and optimizing wettability can boost heat transfer efficiency and accelerate heterogeneous bubble nucleation. Specifically, liquid film detachment time was reduced by 1888 ps on hydrophobic and 1370 ps on hydrophilic surfaces. The study also shows a subtle relationship between roughness and boiling performance. On different wettable surfaces, the average heat flux of hydrophobic surfaces can increase by up to 9.21% and that of hydrophilic surfaces by up to 7.90% with increasing roughness. Surface B2 (hydrophilic, roughness = 1.13), despite being rougher than B1 (hydrophilic, roughness = 1.09), has a delayed detachment time, highlighting the complex interdependence of surface morphology and fluid dynamics. In addition, the parallel flow arrangement promotes bubble nucleation by adjusting the flow field distribution while slowing bubble growth. The explosive boiling time is delayed by 6.5% compared to the staggered arrangement. These findings offer insights for designing more efficient thermal management systems in high-performance microelectronics.
In this study, the synergistic effect of the roughness of different wettabilities micro/nano-structures and their arrangement on the flow boiling was systematically analyzed by molecular dynamics simulation method based on the open-source software LAMMPS. The wall material is modelled as an L-J solid with a face-centered cubic (FCC) lattice structure, with a lattice constant of 3.5 Å. The structure was divided into three parts: the fixed layer, the thermostatic layer, and the heat-conducting layer. The L-J fluid system was composed of a FCC lattice arrangement, with a lattice constant of 5.8 Å in the liquid region and 32 Å in the vapor region. All interatomic interactions are described by the Lennard-Jones (L-J) potential function.
微电子设备集成和性能方面的不断进步加剧了热管理挑战。表面粗糙度和润湿性是流动沸腾过程中气泡成核的关键参数，但其纳米尺度效应尚未得到充分理解。本研究使用分子动力学模拟来探索湿润的微/纳米结构表面如何影响流动沸腾，重点关注粗糙度、排列和驱动力。结果表明，施加力并优化润湿性可以提高传热效率并加速异质气泡成核。具体而言，疏水性表面的液膜脱离时间减少了1888皮秒，亲水性表面减少了1370皮秒。该研究还表明粗糙度与沸腾性能之间存在微妙关系。在不同润湿性的表面上，随着粗糙度增加，疏水性表面的平均热流可增加高达9.21%，亲水性表面可增加高达7.90%。表面B2（亲水性，粗糙度 = 1.13）尽管比B1（亲水性，粗糙度 = 1.09）更粗糙，但具有延迟的脱离时间，突出了表面形态与流体动力学之间复杂的相互依存关系。此外，平行流排列通过调整流场分布促进气泡成核，同时减缓气泡生长。与交错排列相比，爆发沸腾时间延迟了6.5%。这些发现为在高性能微电子中设计更高效的热管理系统提供了见解。
在本研究中，基于开源软件LAMMPS，采用分子动力学模拟方法系统分析了不同润湿性微/纳米结构的粗糙度及其排列对流动沸腾的协同作用。壁材料被建模为具有面心立方（FCC）晶格结构的L-J固体，晶格常数为3.5埃。结构分为三个部分：固定层、恒温层和导热层。L-J流体系统由FCC晶格排列组成，液体区域的晶格常数为5.8埃，蒸汽区域为32埃。所有原子间相互作用均由 Lennard-Jones（L-J）势函数描述。
