The Developing Plane Channel Flow over Water-Repellent Surface Containing Transverse Grooves and Ribs
Keywords:entrance length, superhydrophobic, surface roughness, laminar flow, wall slip
This study presents a numerical investigation on developing flow in a plane channel having alternating superhydrophobic transverse grooves and ribs patterned on both upper and lower walls. Pressure-driven flow at low Reynolds number (i.e., = 1) is considered. The numerical results show that the presence of superhydrophobic surfaces has a visible influence on the velocity profile, centerline velocity and the hydrodynamic entrance length. It is worth highlighting that the hydrodynamic entrance length arising from flow over superhydrophobic transverse grooves are longer than that of smooth surface. This lead to suggestion that, by having transversely aligned groove mounted surface with hydrophobic coating, the fully developed flow region can be delayed. It is also found that, despite having the same gas area fraction, the scale of the microstructure features could directly influence the hydrodynamic entrance length, as well as the velocity profile and the centerline velocity distribution.