Abstract: 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.

Key words: biofouling, microstructure, antifouling, drag reduction, numerical simulation