Fluid Drag Reduction with Shark-Skin Riblet Inspired Microstructured Surfaces

• Published in: Advanced functional materials Vol. 23; no. 36; pp. 4507 - 4528
• Main Authors: Bixler, Gregory D., Bhushan, Bharat
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 25.09.2013; WILEY‐VCH Verlag
• Subjects: biomimetics; Channels; Computational fluid dynamics; Drag; Fluid flow; low drag materials; Riblets; shark skin; Sharks; Turbulence; Turbulent flow
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201203683

Engineering marvels found throughout living nature continually provide inspiration to researchers solving technical challenges. For example, skin from fast‐swimming sharks intrigue researchers since its low‐drag riblet microstructure is applicable to many low drag and self‐cleaning (antifouling) applications. An overview of shark skin related studies that have been conducted in both open channel (external) and closed channel (internal) flow experiments is presented. Significant work has been conducted with the open channel flow, and less with closed channel flow. The results provide design guidance when developing novel low drag and self‐cleaning surfaces for applications in the medical, marine, and industrial fields. Experimental parameters include riblet geometry, continuous and segmented configurations, fluid velocity (laminar and turbulent flow), fluid viscosity (water, oil, and air), closed channel height dimensions, wettability, and scalability. The results are discussed and conceptual models are shown suggesting the effect of viscosity, coatings, and the interaction between vortices and riblet surfaces. Engineering marvels found throughout living nature provide inspiration to researchers solving technical challenges. For example, the skins of fast‐swimming sharks intrigue researchers because their riblet microstructures lead to low drag, self‐cleaning, and antifouling properties. An overview of shark skin related studies that have been conducted in both open and closed channel flow experiments is presented. Adapted with permission.24 Copyright 2012, Royal Society of Chemistry.