表面润湿性和微结构在蒸汽冷凝相变传热过程中发挥着主导作用。受瓶子草绒毛表面梯级沟槽结构在雾气中高效集水现象启发，本项目在条纹型亲疏水异质表面基础上，配置梯级沟槽，提出仿生亲疏水异质梯级沟槽表面用于强化冷凝传热。基于Cantor集分形开展瓶子草绒毛表面梯级沟槽的仿生重构并据此研制新型强化冷凝表面，结合高速显微成像技术开展该表面冷凝传热性能测试及可视化实验；基于格子Boltzmann方法建立冷凝相变传热理论模型并数值求解；探析仿生亲疏水异质梯级沟槽冷凝表面液滴生长合并、液膜流动抽吸以及液滴、液膜融合振荡全过程的协同输运机制，阐明表面润湿性、梯级沟槽形貌和冷凝工况参数对冷凝传热特性的影响规律，掌握滴膜共存冷凝模式及发生条件，进而揭示仿生亲疏水异质梯级沟槽表面强化冷凝传热机理。本项目不仅有助于进一步完善微尺度相变传热及多相界面动力学基础理论，也将为仿生表面冷凝调控和优化设计提供关键技术支撑。

Surface wettability and microstructures play an important role in phase change heat transfer of steam condensation. Inspired by the process of fog harvesting in the hierarchical grooved surface of a Sarracenia trichome, a new type of hydrophobic-hydrophilic heterogeneous surface with bionic hierarchical grooves is proposed to enhance condensation heat transfer, which upgrades the striped hydrophilic-hydrophobic heterogeneous surface. The fractal Cantor structure is introduced to characterize and reconstruct the hierarchical grooved surface of a Sarracenia trichome and a new type of enhanced condensation surface is fabricated accordingly. The project will measure the heat transfer performance of condensation on the fabricated surface and conduct visualization experimental investigation on the dynamic evolution of vapor-liquid interface via high speed microscope camera. In addition, a lattice Boltzmann model of condensation heat transfer process is developed and numerically analyzed. In this model, the surface wettability, topography of the hierarchical grooved structure and the dynamic behavior of vapor-liquid interface are considered. Through the visualization experiment and mesoscopic simulation, the project will elucidate the cooperative transport mechanism of droplet growth and coalescence, liquid film flow and suction, droplet and liquid film fusion and oscillation on the present surface during condensation. The effects of surface wettability, morphology of hierarchical grooved structure, and condensation parameters on the characteristics of condensation heat transfer are going to be expounded. The occurrence condition for the dropwise-filmwise condensation will be clarified. The mechanism of condensation heat transfer enhancement on the hydrophobic-hydrophilic heterogeneous surface with bionic hierarchical grooves will be revealed. This project will be of significant scientific value in the theory development for microscale phase change heat transfer and interface dynamics. It will also provide important technical supports for the optimization design of bionic condensation surface.