Drag reduction performance and mechanism of flexible conical microstructure film inspired by pufferfish epidermis. (1st March 2023)

• Record Type: Journal Article
• Authors: Zhang, Yaosheng; Fan, Dongliang; Feng, Xiaoming; Hu, Yushen; Shi, Jin; Tian, Guizhong
• Is Part Of: Ocean engineering. Volume 271(2023)
• Publication Date: 2023-03-01
• Subjects: Pufferfish epidermis -- Drag reduction film -- Flexible conical microstructures -- Model ship experiment -- Water tunnel experiment; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2023.113760
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Flexible bionic drag reduction surfaces have attracted increasing attention in recent years owing to its potential to address the daunting energy crisis. Inspired by the skin of pufferfish, a flexible conical microstructure film with effective drag reduction is designed. The film has the advantages of cost-effective and tensile-bending resistance to meet commercial applications. The low price of raw materials and rapid solidification at room temperature are the core of cost reduction, and the manufactured film can withstand a maximum tensile force of 70 N and a strain of 484%. The practical application effect of the film has been confirmed by model ship tests, and it still has stable drag reduction ability after multiple stretching and bending. The water tunnel experiment results show that the drag-reducing efficiency of the flexible conical microstructure film is 10.65%–12.04% compared to the rigid plane, in which the conical topography suppresses turbulence burst, whereas the flexible surface has the effect of absorbing turbulent energy to buffer the near-wall fluid. The coupling effect enhances drag-reducing efficiency. Therefore, the flexible conical microstructure film in this work provides a practical and commercialized fluid drag reduction approach for ships, underwater vehicles, and pipeline transportation. Highlights: The flexible bionic film has cost-effectiveness and tensile-bending resistance. Model ship experiments proved that the flexible bionic film has an acceleration effect of 1.89%–7.57%. The drag reduction efficiency of the flexible bionic film is 10.65%–12.04% measured by water tunnel experiments. The combination of conical microstructure and flexibility can absorb turbulent energy and weaken turbulent burst.