基于格子Boltzmann方法的液润表面减阻规律

The drag reduction mechanism of liquid-infused surface based on lattice boltzmann method

  • 摘要:
    目的 近年来,液润表面(LIS)作为一种新型的减阻表面被提出。它将传统疏水表面微沟槽中残存的气体替换为润滑油,进而提高了减阻效果的稳定性。为了更全面地认识液润表面,研究润滑油溶解性对滑移长度的影响。
    方法 基于格子Boltzmann方法(LBM)伪势模型,对液润表面的滑移现象进行数值模拟,研究润滑油溶解密度和外部剪切率对滑移长度的影响规律。
    结果 液润表面可以产生滑移现象,当润滑油完全混溶或极难溶时,滑移长度与组分间分子作用强度有较好的线性关系。
    结论 润滑油难溶于水时,组分间作用力越大,减阻效果越好。且滑移长度不显著依赖于剪切率,润滑油的减阻特性与传统超疏水壁面的减阻特性有相似性。

     

    Abstract:
    Objectives Newly proposed in recent years, the liquid-infused surface (LIS) is a drag reduction surface which replaces the residual air conserved by the microgrooves of a traditional superhydrophobic surface with a lubricant, thereby vastly improving the stability of the drag reduction level. To fully understand the drag reduction stability of LIS, this paper focuses on the influence of lubricant solubility on drag reduction.
    Methods Based on the lattice Boltzmann method (LBM), we simulated a conserving lubricant microstructure with microflow and studied the influence of the lubricant's dissolved density and shear velocity on slip length.
    Results The liquid-infused surface results in a slip phenomenon, and there exists a linear relationship between slip length and cohesion force strength among its particles when the lubricant is completely dissolved or difficult to dissolve.
    Conclusions With greater cohesion force strength among its particles, a lubricant can result in more promising drag reduction when it is difficult to dissolve. The lubricant's shear velocity has little influence on slip length. The properties of the lubricant are similar to those of a traditional superhydrophobic surface.

     

/

返回文章
返回