Motivation

  • Skin friction drag contributes to 60-70% of the total drag for a cargo ship, 80% for a tanker and 90% for underwater vehicles.
  • Shipping alone accounts for 8.5% of the global oil supply and 3.3% of CO2 emissions.
  • Just 16 of the world’s largest ships can produce as much lung-clogging sulphur pollution as all the world’s car.
  • Superhydrophobic (SHPo) surface is able to produce significant drag reduction to reduce fuel consumption and increase speed of the ships.

Milestones

2006: Large slip was obtained on "Nanoturf" (Published in PRL)

 

2008: Design rules of SHPo surface drag reduction in laminar flow (Published in PRL)

2011: First sustainable "active" SHPo surface for practical drag reduction (Published in PRL, highlighted in Nature)

 2014: 75% drag reduction in turbulent flow !! (Published in JFM)

2014: SHPo states could last infinitely underwater!! But don`t be over-optimistic (Published in PRL)

2020: 30% drag reduction on a real boat! (Published in Physical Review Applied)

Next: Practical drag (power) reduction for marine vessels

Publications

  1. M. Xu, B. Arihara, H. Tong, N. Yu, Y. Ujiie, and C.-J. Kim, “Low-profile Direct Shear Sensor to Mount and Test Surface Samples”, Experiments in Fluids, Vol. 61, Issue 3, March 2020, 82(13). (doi: 10.1007/s00348-020-2922-z)
  2. M. Xu, A. Grabowski, N. Yu, G. Kerezyte, J.-W. Lee, B. R. Pfeifer, and C.-J. Kim, “Superhydrophobic Drag Reduction for Turbulent Flows in Open Water,” Physical Review Applied, Vol. 13, Issue 3, March 2020, 034056(10). (doi: 10.1103/PhysRevApplied.13.034056)
  3. M. Xu, G. Sun, and C.-J. Kim, "Infinite Lifetime of Underwater Superhydrophobic States", Physical Review Letters, vol. 113, Sep 2014, p. 136103. (doi: 10.1103/PhysRevLett.113.136103)
  4. H. Park, G. Sun, and C.-J. Kim, “Superhydrophobic turbulent drag reduction as a function of surface grating parameters,” Journal of Fluid Mechanics, Vol. 747, May 2014, pp. 722-734. (doi: 10.1017/jfm.2014.151)
  5. C. Lee and C.-J. Kim, “Wetting and Active Dewetting Processes of Hierarchically Constructed Superhydrophobic Surfaces Fully Immersed in Water,” Journal of Microelectromechanical Systems, Vol. 21, No. 3, June 2012, pp. 476-483. (doi: 10.1109/JMEMS.2012.2184081)
  6. C. Lee and C.-J. Kim, “Influence of Surface Hierarchy of Superhydrophobic Surfaces on Liquid Slip,” Langmuir, Vol. 27, Issue 7, April 2011, pp. 4243-4248. (doi: 10.1021/la104368v)
  7. C. Lee and C.-J. Kim, “Underwater Gas Restoration and Retention on Superhydrophobic Surfaces for Drag Reduction,” Physical Review Letters, Vol. 106, No. 1, January 2011, 14502(4). (doi: 10.1103/PhysRevLett.106.014502)
  8. C. Lee and C.-J. Kim, “Maximizing the Giant Liquid Slip on Superhydrophobic Microstructures by Nanostructuring Their Sidewalls",?Langmuir, Vol. 25, Issue 21, November 2009, pp. 12812-12818. (doi: 10.1021/la901824d)
  9. C. Lee, C.-H. Choi, and C.-J. Kim, "Structured surfaces for a giant liquid slip", Physical Review Letters, vol. 101, Aug 2008, p. 64501. (doi: 10.1103/PhysRevLett.101.064501)
  10. C.-H. Choi and C.-J. Kim, "Large slip of aqueous liquid flow over a nanoengineered superhydrophobic surface", Physical Review Letters, vol. 96, Feb 2006, p. 066001. (doi: 10.1103/PhysRevLett.96.066001)