Abstract
We studied the effect of hydrophobic microstructural shape on laminar drag reduction experimentally. Deep truncated cone holes are machined into a test wall surface, and the surface is coated with triazine thiol to induce hydrophobicity. The aperture ratios of the test walls are 10% and 20%. Drag reduction was estimated by measuring the pressure loss in microchannels. The Reynolds number range for drag reduction in the case of the test walls was found to be wider than that in the case of conventional walls. Additionally, the percentage of drag reduction for test walls is comparable to that for conventional walls with smaller aperture ratios.
