基于表面拓扑结构和浸润性的流动减阻机理研究

项目名称： 基于表面拓扑结构和浸润性的流动减阻机理研究

项目编号： No.11272176

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 姚朝晖

作者单位： 清华大学

项目金额： 82万元

中文摘要： 本项目是研究表面拓扑结构和表面浸润性对流动减阻的影响及机理探讨，近些年来由于其潜在的各方面优点，相关流动减阻技术受到越来越多的关注。但是，目前的研究多局限于一级结构超疏水表面的压力驱动流的层流减阻。本项目计划从实验和计算两方面同时开展，进行一级/多级微纳结构的不同表面拓扑结构和不同表面浸润性的湍流流动减阻研究。在实验研究中采用PIV和Micro-PIV等技术对近壁区流场进行精细测量，分析表面拓扑结构和浸润性对雷诺应力项和湍流强度等参数的影响，揭示湍流减阻的机理。并进行流动驱动方式对流动减阻效果的研究，揭示剪切驱动流导致的超疏水表面流动增阻现象产生的机理。在计算研究中，开发既可有效模拟气液界面又能确保在压力驱动流中维持液体密度不变的改进LBGK方法，进行表面拓扑结构与表面浸润性等参数对表面滑移长度和气液界面形状影响的研究。此外，将优化算法与LBGK方法相结合，进行微纳尺寸参数的合理配比研究。

中文关键词： 超疏水表面；微纳二级结构；流动减阻；涡结构；改进的LBGK方法

英文摘要： This project is flow drag reduction study based on the surface topology and wetting property. Drag reduction techniques have received more and more attention in recent years due to their promising applications with great benefits in many areas. However, most of the current studies have focused on the superhydrophobic surface with micro- and nano- stuctures. Most of the flows have been studied are laminar flows driven by the pressure gradients. In the project, influences of micro-, nano- and hierarchical structures, as well as their wetting properties (superhydrophobic and superhydrophilic) on the drag reduction of turbulent flow will be studied. The project will be carried out from both of experiments and calculations. In the experimental study, using technologies such as particle image velocimeter (PIV) and Micro-PIV, flow field of the near-wall region will be measured accurately, and the effect of surface topology and wetting property on the Reynolds stress terms and the turbulence intensity,etc.will be analysed. Apart from pressure-driven flows, effects of superhydrophobic surfaces on the shear-driven flows will be paid more attention. The mechinism of drag increase on the superhydrophobic surface in the shear-driven flows, will be revealed. In the simulations, an improved LBGK method which not only can effe

英文关键词： superhydrophobic surface；micro-nano hierarchical structured surfaces；flow drag reduction；vortex structure；improved LBGK method