Numerical simulation of superhydrophobic surface's flow field characteristic and drag reduction rule

Based on the numerical simulation model of superhydrophobic surfaces flow field, the flow field characteristics and the drag reduction law are studied with superhydrophobic surfaces with the microcosmic topography in turbulence. The results show that the prominent slip flows on the gas-liquid interface and the conjugated streamwise vortex near the microcosmic topography of superhydrophobic surfaces appear. These factors inhibit the turbulent fluctuation, reduce Reynolds stress and energy loss together, so that the superhydrophobic surfaces generate drag reduction effect; the drag reduction of superhydrophobic surfaces increases with the increase of the free shear area ratios and increases with the increase of the topography periods. There is a qualitative relationship between the drag reduction and the slip, namely the greater slip, the better drag reduction effect.