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Mechanics in Engineering ›› 2013, Vol. 35 ›› Issue (4): 20-24.doi: 10.6052/1000-0879-13-098

• Applied Research • Previous Articles     Next Articles

DRAG REDUCTION IN TURBULENT FLOWS OVER SUPERHYDROPHOBIC SURFACES WITH MICRO-NANO TEXTURES

LU Si, YAO Zhaohui, HAO Pengfei, FU Chengsong   

  1. Department of Engineering Mechanics, School of Aerospace, Tsinghua University, Beijing 100084, China
  • Received:2013-03-21 Revised:2013-06-03 Online:2013-08-08 Published:2013-08-26

Abstract:

The superhydrophobic surfaces have a very wide range of potential applications in the modern life and industrial production due to their excellent properties. In this paper, a kind of superhydrophobic surface was fabricated by pasting micro-nano particles onto an aluminium or PMMA (polymethylmethacrylate) substrate. The micro-nano particles were obtained by carbon nanotubes winding technology and hydrophobic processing. The pressure drop measurements were carried out in the channel with superhydrophobic surfaces above. Compared with the common surface channel, the flow resistance decreases by about 22.8% at most in the laminar flow. In the turbulent flow, the drag reduction can reach 53.3%. The velocity field in the channel with such superhydrophobic surfaces was measured by particle image velocimetry (PIV) technology. Through the slip velocities in the superhydrophobic surface and the turbulent fluctuations, the physical mechanism is revealed to show that the turbulent friction reduction effects are apparently better than in cases of laminar flows.

Key words:

superhydrophobic surface|micro-nano dual-scale structures|turbulent flow|drag reduction|slip velocity

CLC Number: 

  • O357.1