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A prediction of drag reduction by entrapped gases in hydrophobic transverse grooves

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Abstract

The drag reduction effect of super-hydrophobic surface induced by the entrapped gas is unstable due to the gradual disappearance of the trapped gas. In this paper, a hydrophobic transverse grooved surface was designed to sustain gas in valleys. A detail numerical simulation was presented to investigate the flow field near the proposed surface. When water flowed over this surface, the entrapped gas was blocked by the ridges and the solid-liquid interface was replaced by the liquid-gas interface due to the entrapped gas, furthermore the micro-vortex formed in the groove. Because there was an effective slippage between water and solid induced by the entrapped gas, the velocity gradient of boundary layer decreased, which contributed to a remarkable drag reduction effect. Additionally, considering the extra undesired pressure drag reduction which negatively impacted the drag reduction effect of this method, the total drag coefficient including the viscous drag coefficient and the pressure coefficient was analyzed. An effective drag reduction rate of about 15% was achieved and the effect of this method was confirmed by experiments conducted in a high-speed water tunnel when grooves were optimized.

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References

  1. Jiang C G, Xin S C, Wu C W. Drag reduction of a miniature boat with superhydrophobic grille bottom. AIP Adv, 2011, 1(3): 032148

    Article  Google Scholar 

  2. Zhang D Y, Li Y Y, Han X, et al. High-precision bio-replication of synthetic drag reduction shark skin. Chin Sci Bull, 2011, 56(9): 938–944

    Article  MathSciNet  Google Scholar 

  3. Walsh M J. Riblets as a viscous drag reduction technique. AIAA J, 1983, 21(4): 485–486

    Article  Google Scholar 

  4. Choi J, Jeon W P, Choi H. Mechanism of drag reduction by dimples on a sphere. Phys Fluids, 2006, 18: 041702

    Article  Google Scholar 

  5. García-Mayoral R, Jiménez J. Drag reduction by riblets. Phil Trans R Soc A, 2011, 369(1940): 1412–1427

    Article  Google Scholar 

  6. Ranjan P, Ranjan A R, Singh A P. Computational analysis of frictional drag over transverse grooved flat plates. Int J Eng Sci Tech, 2011, 3(2):110–116

    Google Scholar 

  7. Martell M B, Rothstein J P, Perot J B. An analysis of superhydrophobic turbulent drag reduction mechanisms using direct numerical simulation. Phys Fluids, 2010, 22(06): 065102

    Article  Google Scholar 

  8. Martell M B, Perot J B, Rothstein J P. Direct numerical simulations of turbulent flows over superhydrophobic surfaces. J Fluid Mech, 2009, 620(1): 31–41

    Article  MATH  Google Scholar 

  9. Shirtcliffe N J, McHale G, Newton M I, et al. Superhydrophobic copper tubes with possible flow enhancement and drag reduction. ACS Appl Mater Inter, 2009, 1(6): 1316–1323

    Article  Google Scholar 

  10. Mowla D, Naderi A. Experimental study of drag reduction by a polymeric additive in slug two-phase flow of crude oil and air in horizontal pipes. Chem Eng Sci, 2006, 61(5): 1549–1554

    Article  Google Scholar 

  11. Yang S Q, Dou G. Turbulent drag reduction with polymer additive in rough pipes. J Fluid Mech, 2010, 642(1): 279–294

    Article  MATH  Google Scholar 

  12. Li F C, Kawaguchi Y, Yu B, et al. Experimental study of drag-reduction mechanism for a dilute surfactant solution flow. Int J Heat Mass Tran, 2008, 51(3): 835–843

    Article  Google Scholar 

  13. Ceccio S L. Friction drag reduction of external flows with bubble and gas injection. Annu Rev Fluid Mech, 2010, 42: 183–203

    Article  Google Scholar 

  14. Gutierrez-Torres C C, Hassan Y A, Jimenez-Bernal J A. Turbulence structure modification and drag reduction by microbubble injections in a boundary layer channel flow. J Fluids Eng, 2008, 130(11): 111304

    Article  Google Scholar 

  15. Vakarelski I U, Marston J O, Chan D Y C, et al. Drag reduction by Leidenfrost vapor layers. Phys Rev Lett, 2011, 106(21): 214501

    Article  Google Scholar 

  16. Kumari N, Garimella S V. Electrowetting-induced dewetting transitions on superhydrophobic surfaces. Langmuir, 2011, 27(17): 10342–10346

    Article  Google Scholar 

  17. Lee C, Kim C J. Underwater restoration and retention of gases on superhydrophobic surfaces for drag reduction. Phys Rev Lett, 2011, 106(1): 014502

    Article  Google Scholar 

  18. Hara K, Suzuki T, Yamamoto F. Image analysis applied to study on frictional-drag reduction by electrolytic microbubbles in a turbulent channel flow. Exp Fluids, 2011, 50(3): 715–727

    Article  Google Scholar 

  19. Gao X, Jiang L. Biophysics: Water-repellent legs of water striders. Nature, 2004, 432(7013): 36–36

    Article  Google Scholar 

  20. Fukagata K, Kasagi N, Koumoutsakos P. A theoretical prediction of friction drag reduction in turbulent flow by superhydrophobic surfaces. Phys Fluids, 2006, 18(5): 051703

    Article  Google Scholar 

  21. Belyaev A V, Vinogradova O I. Effective slip in pressure-driven flow past super-hydrophobic stripes. J Fluid Mech, 2010, 652: 489–499

    Article  MATH  Google Scholar 

  22. Tsai P, Peters A M, Pirat C, et al. Quantifying effective slip length over micropatterned hydrophobic surfaces. Phys Fluids, 2009, 21(11): 112002

    Article  Google Scholar 

  23. Choi C H, Ulmanella U, Kim J, et al. Effective slip and friction reduction in nanograted superhydrophobic microchannels. Phys Fluids, 2006, 18(8): 087105

    Article  Google Scholar 

  24. Choi C H, Kim C J. Large slip of aqueous liquid flow over a nanoengineered superhydrophobic surface. Phys Rev Lett, 2006, 96(6): 066001

    Article  MathSciNet  Google Scholar 

  25. Lee C, Choi C H, Kim C J. Structured surfaces for a giant liquid slip. Phys Rev Lett, 2008, 101(6): 064501

    Article  Google Scholar 

  26. Lee C, Kim C J. Maximizing the giant liquid slip on superhydrophobic microstructures by nanostructuring their sidewalls. Langmuir, 2009, 25(21): 12812–12818

    Article  Google Scholar 

  27. Teo C J, Khoo B C. Flow past superhydrophobic surfaces containing longitudinal grooves: Effects of interface curvature. Microfluid Nanofluid, 2010, 9(2–3): 499–511

    Article  Google Scholar 

  28. Byun D, Kim J, Ko H S, et al. Direct measurement of slip flows in superhydrophobic microchannels with transverse grooves. Phys Fluids, 2008, 20(11): 113601

    Article  Google Scholar 

  29. Govardhan R N, Srinivas G S, Asthana A, et al. Time dependence of effective slip on textured hydrophobic surfaces. Phys Fluids, 2009, 21(5): 052001

    Article  Google Scholar 

  30. Cassie A B D, Baxter S. Wettability of porous surfaces. Trans Faraday Soc, 1944, 40: 546–551

    Article  Google Scholar 

  31. Wenzel R N. Resistance of solid surfaces to wetting by water. Ind Eng Chem, 1936, 28(8): 988–994

    Article  Google Scholar 

  32. Wang J D, Chen D R. Criteria for entrapped gas under a drop on an ultrahydrophobic surface. Langmuir, 2008, 24(18): 10174–10180

    Article  Google Scholar 

  33. Ding B, Ogawa T, Kim J, et al. Fabrication of a super-hydrophobic nanofibrous zinc oxide film surface by electrospinning. Thin Solid Films, 2008, 516(9): 2495–2501

    Article  Google Scholar 

  34. Dou Z L, Wang J D, Yu F, et al. Fabrication of a micro-structured surface based on interfacial convection for drag reduction. Chin Sci Bull, 2011, 56(7): 626–632

    Article  Google Scholar 

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Correspondence to JiaDao Wang.

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Wang, B., Wang, J. & Chen, D. A prediction of drag reduction by entrapped gases in hydrophobic transverse grooves. Sci. China Technol. Sci. 56, 2973–2978 (2013). https://doi.org/10.1007/s11431-013-5395-y

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  • DOI: https://doi.org/10.1007/s11431-013-5395-y

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