基于固壁微空化的柔性滑移边界形成与润滑机理

Drag force will be generated on a solid body when it moves in the water, and the friction force is the main part of the drag force that generates on the surface of the solid wall. Drag reduction is an important technique to save energy and increase working efficiency. In this project, special surface patterns are to be fabricated with designed wettability to induce the micro cavitation on the solid wall in water. Micro cavitation bubbles are to be generated and adhered on the patterned surface. Therefore, the bubbles will form a solid-gas-liquid multiphase structure to reduce the friction force on the surface. Then, modified lubrication equation will be derived for the deformable slip boundary of the cavitation bubble, and the lubrication mechanism of this boundary condition is to be investigated. The results of this project will develop the theory and the method of drag reduction in the field of tribology, and it will have potential applications in lubrication engineering and channel transportation.

固液间的摩擦阻力是固体在液体中运动所受到的主要阻力之一，减少固液界面间的摩擦阻力是提高效率和节约能源的重要手段。本研究拟通过构造壁面形貌和润湿性诱发固体壁面局部的微尺度空化，使得微空泡在壁面生长和吸附，形成具有固－气－液三相结构的润滑界面以降低固壁表面的摩擦阻力；并通过建立泡壁柔性滑移边界的润滑方程明晰其润滑和减阻机理。研究结果对于发展摩擦学润滑理论和减阻技术，提高润滑效率有重要的理论意义和明确的应用前景。

本项目通过构造壁面形貌和润湿性在固体壁面上形成的气液柔性滑移界面，进行了空化界面观测；分析了空泡与固壁表面相互作用机理，并进行了空泡运动数值模拟，从而最终完成了基于固壁柔性滑移界面的减阻效应的测量和计算。研究揭示了微、纳米气泡在壁面的吸附、生长和脱附过程，以及在此过程中气泡吸附形态对减阻效应的影响，其研究结果对于发展摩擦学润滑理论和减阻技术有重要的理论意义。围绕上述研究内容在Applied physics letters、Langmuir、ACS applied materials and interfaces、Tribology letters 等期刊上发表SCI 检索论文8 篇；国际会议邀请报告1次，荣获2014 年“亚太材料研究学会年会报告一等奖”。