MSc project: Can a bird-feather-inspired surface texture reduce turbulent drag?


Living in a world with an ever increasing human population and diminishing fuel supplies, reduction of fuel consumed for transportation is highly desirable. Drag reducing (DR) techniques are promising in this respect. Drag on, for instance, a ship can be reduced not only by optimizing its hull form, but also by changing its surface texture. With a shark-skin-inspired texture a DR of 10% has been measured for fully developed turbulent plane channel flow [1]. Recently, another bio-inspired texture has been proposed, namely the texture found on bird flight feathers (see Figure 1). In an experimental study, a bird-feather-inspired texture gave rise to 20% drag reduction [2], twice as much as for the shark-skin-inspired texture.



You will help to answer the question: how and under what conditions can a bird-feather-inspired texture reduce turbulent drag? You will perform an experimental study in a water tunnel. We envision the following steps:

* Make the water tunnel suitable for accurate drag measurements

* Collaborate with a 3D-printing expert to manufacture the textures to be studied

* Perform the drag measurements for several textures

* Visualize the turbulent flow by means of Particle Image Velocimetry (PIV), a novel laser-based imaging technique [3].



For more information, please contact Henk Benschop:



[1] D. W. Bechert, M. Bruse, W. Hage, J. G. T. Van der Hoeven, and G. Hoppe. Experiments on drag-reducing surfaces and their optimization with an adjustable geometry. Journal of Fluid Mechanics, 338(5):59-87, 1997.

[2] H. Chen, F. Rao, X. Shang, D. Zhang, and I. Hagiwara. Flow over bio-inspired 3D herringbone wall riblets. Experiments in Fluids, 55(3):1-7, 2014a.

[3] Adrian R. J., Westerweel J. Particle image velocimetry. New York: Cambridge University Press; 2011.