Abstract
In this study, we investigated the influence of wall surface roughness on the pressure drop in microchannel flow of drag reducing fluids with two different channel heights, 100 and 50 μm. Tested channel surface roughness are Ra = 0.2, 1.0, 1.6, 2.5, 4.8, and 10.0 μm. Moreover, we changed surface wettability on these surfaces, namely hydrophilic or hydrophobic. The experiment showed the pressure drop increased with an increase of surface roughness. In case of Ra > 1.0 μm, the pressure drop on hydrophobic surfaces were lower than that on hydrophilic surfaces. For polymer solutions, the pressure drop decreased in the case of hydrophilic surface roughness. On the other hand, for hydrophobic surface roughness, the pressure drop increased.
