Numerical Simulation of flow and drag reduction characteristic of hydrophobic surface

For the drag reduction potential application of hydrophobic surface, VOF multiphase model and RNG k - ε turbulent model are adopted to simulate hydrophobic surface flow. The numerical simulation results show that: hydrophobic surface microstructures induce circular low-speed vortex which can produce certain cohesive force and they produce certain pressure force at the same time. But the microstructures have no significant effect on the flow field stability and static pressure distributions of near wall area. At the same velocity, as hydrophobic surface free shear area enlarges, pressure force increases and viscous force decreases gradually and the drag reduction of hydrophobic surface decreases gradually. For the hydrophobic surface with the same free shear area ratio, the drag reduction increases gradually with the increase of the velocity in the velocity range of 2.5 m/s and 10m/s.