Open AccessInvestigation of Drag-Reduction Effect of Super-Hydrophilic Surface in Laminar Microchannel Flow
Author(s) -
Hao Luo,
Lichang Lu,
Yuxin Hao,
Xiang Li,
Zhili Dong,
Yang Liu,
Yuanzhe Li
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/804/2/022037
Subject(s) - drag , microchannel , laminar flow , materials science , mechanics , slippage , surface roughness , parasitic drag , reynolds number , flow (mathematics) , composite material , nanotechnology , turbulence , physics
In previous studies of newly fabricated surface-coating materials, the super hydrophilic surface etched by Cu2+/HNO3 exerts higher drag-reduction effect at low Reynolds numbers than the modified superhydrophobic surface even with similar surface structure. In this paper, both experimental and modelling fluid dynamics studies are used to invest the drag-reduction and flow field for these super hydrophilic surfaces in the microchannel. The experimental results showed that the drag-reduction rate would gradually decrease with the velocity increment of medium. Besides, the dissolved gas does play a key role in reducing the shear stress in the near wall flow field by forming the non-shear air/water interface and increasing its wall-slippage effect. Moreover, the flow-field stimulation analysis provides more intuitive schematic diagram velocity magnitude and pressure changes inside the microchannel, and the surface roughness obtained by chemical etching is capable to enhance the drag-reduction effect as well.