Prediction the variation of shark scale’s attack angles in swimming

DOI: 10.5958/0976-0555.2015.00088.6    | Article Id: B-236 | Page : 295-302
Citation :- Prediction the variation of shark scale’s attack angles in swimming.Indian Journal Of Animal Research.2015.(49):295-302
Yuehao Luo*, Yufei Liu and D. Y. Zhang
Address : School of Engineering and Applied Science, The George Washington University, Washington D. C., 20052, USA.


Shark is the fast swimming animal in the ocean, and it is well-known for sharkskin effect. Sharkskin is covered by the tiny and rigid scales, which can stick out of the viscous sublayer and effectively inhibit the occurrence of turbulence and reduce the wall resistance. The longitudinal sections of the scale surface are not parallel to the flowing direction, but at a particular attack angle, which could be considered as a supplement to the mechanism of sharkskin effect. At present, it is almost impossible to observe the variation of scales’ attack angles during the biological shark’s swimming. Although the real sharkskin surfaces with original sizes have been fabricated by the bio-replicated method, the attack angles cannot be exactly controlled, the result of which is that the drag-reducing efficiency of sharkskin with different attack angles cannot be obtained by the experimental methods. In this paper, the highly accurate three dimensional digital model is exactly built through the high-accurate scanning the biological sharkskin, and the micro flow field is investigated comprehensively and deeply, especially that, the influence of scales’ attack angles on drag-reducing efficiency is analyzed, which has the important significance on exploring the sharkskin effect.


Attack angle Biomimetic surface Drag reduction mechanism Numerical simulation Sharkskin.


  1. Bechert D. W., Bruse M., Hage W., Meyer W.. (2000) Fluid mechanics of biological surfaces and their technological application. Naturwissenschaften, 87: 157-171.
  2. Bechert D. W., Bruse M., Hage W., Vanderhoeven J. G. T. and Hoppe G.. (1997) Experiments on drag-reducing surfaces and their optimization with an adjustable geometry. Journal of Fluid Mechanics, 338: 59-87.
  3. Bharat Bhushan. (2009) Biomimetics: lessons from nature-an overview. Philosophical Transactions of the Royal Society A – Mathematical Physical and Engineering Sciences, 367: 1445-1486.
  4. Haecheon Choi, Parviz Moin and John Kim. (1993) Direct numerical simulation of turbulent flow over riblets, Journal of Fluid Mechanics, 255: 503-539.
  5. Johannes Oeffner and George V. Lauder. (2012) The hydrodynamic function of shark skin and two biomimetic applications. Journal of Experimental Biology, 215: 785-795
  6. Lei Jiang, R. Wang, B. Yang, T. J. Li, D. A. Tryk, A. Fujishima, K. Hashimoto, D. B. Zhu. (2000). Binary Cooperative Complementary Nanoscale Interfacial Materials. Pure Appl. Chem., 72: 73-81
  7. Li Wen, James C. Weaver, George V. Lauder. (2014) Biomimetic shark skin: design, fabrication and hydrodynamic function, The Journal of Experimental Biology, 217: 1656-1666.
  8. Luo Yuehao, Zhang Deyuan. (2012) Experimental Research on Biomimetic Drag-Reducing Surface Application in Natural Gas Pipelines. Oil Gas-European Magazine, 38: 213-214.
  9. Luo Yuehao, Zhang Deyuan. (2013) Investigation on fabricating continuous vivid sharkskin surface by bio-replicated rolling method . Applied Surface Science, 282: 370-375.
  10. Luo Yuehao, Zhang Deyuan, Liu Yufei. (2014) Exploring a Method to Effectively Avoid Drop-out of Internal Coating of Natural Gas Pipes. Oil Gas-European Magazine, 40: 96-97.
  11. Luo Yuehao, Liu Yufei. (2014) Numerical simulation of Micro flow field on Biomimetic Sharkskin Drag-Reducing Surface. Advanced Materials Research, 884-885: 378-381.
  12. Luo Yuehao, Zhang Deyuan. (2011) Experimental Research on Improving Wear Resistance of Coating Surface by Magnetron Sputtering. Advanced Materials Research, 189-193: 9-12.
  13. Luo Yuehao, Zhang Deyuan. (2011) Study on the Micro-replication Precision of Shark Skin. Applied Mechanics and Materials, 44-47: 1151-1157.
  14. Luo Yuehao, Zhang Deyuan, Chen Huawei. (2012) Research on Manufacturing Vivid Trans-scale Shark Skin Surface and Drag-Reducing Effect Simulation . Advanced Science Letters, 5: 49-55.
  15. Naresh M. D., Arumugam V., Sanjeevi R. (1997) Mechanical behavior of shark skin. Journal of Bioscience, 22: 431-437
  16. Reif W. E., Dinkelacker A. (1982) Hydrodynamics of the squamation in fast swimming sharks. Neues Jahrbuch fuer Geologie and Palaeontologie, 164: 184-187.
  17. Springer V. G., Gold J. P. (1989) Sharks in question: the Smithsonian answer book [M]. Washington and London: Smithsonian Institution Press, 46-58.
  18. Yuehao Luo, Yufei Liu, Deyuan Zhang, E. Y. K. NG. (2014). Influence of Morphology for Drag Reduction Effect of Sharkskin Surface. Journal of Mechanics in Medicine and Biology, 14: 1450029.
  19. Yuehao Luo. (2015) Recent Progress in Exploring Drag Reduction Mechanism of Real Sharkskin Surface: a Review. Journal of Mechanics in Medicine and Biology, 15: 1530002.
  20. Yuying Yan, Jianqiao Li, Khellil Sefiane. (2006) Biomimetic Approaches to Functional Surfaces, Surface Wetting and Fluids Drag Reduction. Journal of Bionic Engineering, 4: 1-2.
  21. Zhang Deyuan, Luo Yuehao, Chen Huawei. (2011) Application and Numerical Simulation Research on Biomimetic Drag- reducing Technology for Gas Pipelining. Oil Gas-European Magazine, 37: 85-90.
  22. Zhang Deyuan, Luo Yuehao, Chenhuawei, Jiang Xinggang. (2011) Exploring Drag-Reducing Grooved Internal Coating For Gas Pipelines. Pipeline & Gas Journal, 238: 58-60.
  23. Zhang Deyuan, Luo Yuehao, Li Xiang, Chen Huawei. (2011) Numerical Simulation and Experimental Study of Drag-Reducing Surface of A Real Shark Skin. Journal of Hydrodynamics, 23: 204-211.

Global Footprints