摘要
通过湍流状态下超疏水表面的数值模拟,研究超疏水表面湍流流动的速度和剪应力分布,分析其与减阻的内在关系,初步总结出微观结构与减阻率之间的基本规律.数值模拟采用非定常雷诺平均模型,气液两相流则采用VOF模型.结果表明:超疏水表面存在滑移流动和周期分布的剪应力,其不仅可以实现减阻也有可能导致增阻;微结构尺寸对减阻率有显著影响,为了尽可能增大减阻率,矩形微结构的深宽比应大于3∶2,且凹槽间距应尽可能小,凹槽宽度应小于200微米.
Numerical simulation on superhydrophobic surface of turbulent flow is shown. Velocity or shear stress of turbulent flow are provided and basic law between microscopic structure and drag reduction rate is analyzed. In simulation, we use an unsteady Reynolds averaged simulation model and VOF model for gas-liquid two phase flow. It shows that slip flow and cyclical shear stress exist on superhydrophobic surface. It can reduce resistance and increased resistance as well. Microstructure size has significant effect on drag reduction rate. In order to increase drag reduction rate, the aspect ratio of rectangular mierostructure should be greater than 3：2 and the groove spacing should be small, while the groove width should be less than 200 micron.
出处
《计算物理》
CSCD
北大核心
2013年第1期70-74,共5页
Chinese Journal of Computational Physics
基金
国家自然科学基金重点项目(50835009)
青年项目(51109178)
陕西省自然科学基础研究计划项目(2010JQ1009)资助
关键词
湍流
超疏水
减阻
微结构
turbulent flow
superhydrophobic
drag reduction
micro-structured
