Water-trapping and drag-reduction effects of fish Ctenopharyngodon idellus scales and their simulations

Experimental investigations on drag-reduction characteristics of bionic surface with water-trapping microstructures of fish scales

“…Then in the experiment design, we first took the initial velocity of the fish as a reference, and thus the initial velocity was chosen to be 0.66 m/s. Meanwhile, it was found that as the flow speed increased, the drag reduction rate showed a downward trend by using numerical simulation method at different speed ranges (0.66–0.74 m/s) in our previous study 39 . Therefore, the flow-speed range was designed in the 0.66–0.74 m/s.…”

“…Furthermore, the results further showed that the bionic surface with water-trapping microstructures of fish scales had a great drag-reduction effect at low-speed fluid environments. In the previous numerical simulation work, the drag-reduction characteristic of bionic surface with delicate water-trapping microstructures had been researched and detailedly revealed drag-reduction mechanism 39 . Therefore, the experimental results were conformation of the numerical simulation results on the drag-reduction rate, which further verified the drag-reduction characteristics of the bionic surface with water-trapping microstructures.…”

“…And all stable low-speed water areas joined together because of the distribution of all crescents-like units. Therefore, the self-formed fluid-lubrication film could produce a drag-reduction performance 39 . With respect to the as-received fish scales, however, these microstructures also could originally avoid excessive loss of mucus, and then the drag-reduction was realized.…”

“…Therefore, the peculiar functional structures of organism surfaces provide inspiration for solving key problems. According to the previous study 39 , the surface microstructures of the scales of the fish Ctenopharyngodon idellus were observed and analyzed. Then, the optimized 3D models that were designed based on the acquired data established.…”

Crosslinked superhydrophobic films fabricated by simply casting poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-poly(perfluorohexylethyl methacrylate) solution

“…Fig. 1(a) shows the characteristic absorption peak located at 1446 cm −1 represents the CH 3 group in MMA [24]. The peaks at 2932 cm −1 and 2854 cm −1 are due to stretching vibration of -CH 3 and -CH 2 in HEMA, BA and FMA.…”