Based on the model of volume of fluid

two-dimensional fluid laminar flow in superhydrophobic microchannels was numerically simulated with given parabolic gas-liquid interfaces. The effects of several flow and structural parameters on fRe

the normalized slip length and pressure drop were investigated. The results show that superhydrophobic microchannels with rectangular microcavities exhibited significant drag reduction in a way that fRe increased slightly with increase of Reynolds number whereas normalized pressure drop decreased slightly with increase of inlet velocity. When the area ratio of microcavities was increased or the microchannel diameter was decreased

fRe was reduced but normalized pressure drop was enhanced. In case of small microchannel diameter

the area ratio of microcavities significantly affected fRe. With increase of the parabolic height

the ratio of normalized pressure drop and the normalized slip length decreased linearly

however fRe increased linearly. The impact of microcavities on the normalized slip length and the ratio of normalized pressure drop was minimal provided that the microcavity depth was greater than 40% of its width. The dovetail microcavities exhibited the greatest effect on drag reduction

followed by the rectangular

trapezoidal

triangular microcavities in the order of high to low.