摘要
改变壁面微结构形状可提高其表面防污和自清洁性能。采用Fluent对微孔表面近壁区附有微生物下的流动进行了三维数值模拟,分析了近壁区流体的运动学和动力学特征,探讨了微孔表面防止微生物粘附的内在机理。研究表明:在近壁区流场中,微孔内形成顺流向旋涡,使微孔表面上的速度、变形速率及剪切应力呈规律性波动,流场的波动干扰了微生物的运动,使其较难粘附在微脊上;微孔成为一个有限边界且具有较高剪切应力的孤立区域,从而抑制了微生物在微孔内的聚集和附着。孔径为5μm、孔间距为2μm、且顺列布置的微孔结构表面具有较大的变形速率和剪切应力波动值,并能减小微通道的流动阻力。
Changing the wall microstructure geometry can improve the performance of surface antifouling and selfcleaning. A 3D numerical simulation of microfluidic in the near-wall region attached with microorganisms is performed with Fluent, and the kinetic and dynamic characteristics of fluid in the near wall region are examined. The inherent mechanism of antifouling on microwell surfaces is discussed. Results reveal that streamwise vortices are formed in the microwells, thus the distinctly periodic fluctuations of velocity, strain rate and wall shear stress on microwell surfaces are exhibited, resulting in the interference on microorganisms migration and the harder adhesion of microorganisms to microridges. Additionally, microwell evolves a finite boundary and isolated region with high wall shear stress, which inhibits the aggregation and adhesion of microorganisms in the microwells. In this study, the microwell surface of in-line arrangement with microwell gap of 2 μm and microwell radius of 5 μm can produce larger fluctuation values of strain rate and wall shear stress and reduce the flow drag of the channels.
作者
李春曦
薛全喜
张硕
叶学民
Li Chunxi, Xue Quanxi, Zhang Shuo, Ye Xuemin(Key Lab of Condition Monitoring and Control for Power Plant Equipment of Education Ministry （North China Electric Power University）, Baoding 071003, China)
出处
《系统仿真学报》
CAS
CSCD
北大核心
2018年第10期3903-3913,共11页
Journal of System Simulation
关键词
生物污损
微结构
防污
减阻
数值模拟
biofouling
microstructure
antifouling
drag reduction
numerical simulation
