Focus on Bioinspired Textured Surfaces toward Fluid Drag Reduction: Recent Progresses and Challenges

Abstract

After a long period of biological evolution, natural creatures will inevitably evolve body surfaces suitable for the living environment. The functions of natural biological surfaces are abundant and powerful, including antiadhesion, self‐cleaning, drag reduction, anti‐icing, wear resistance, and other characteristics. In the context of coping with the energy crisis, inspired by natural biological surface microstructures, researchers explore biomimetic surface microstructures that reduce fluid drag and investigate the mechanisms of drag reduction. Herein, mainly the current state of research on biomimetic textured surfaces that can be applied to fluid drag reduction is reviewed and the microstructures’ morphology, drag reduction mechanisms, and the fabrication techniques of textured surfaces are discussed in detail. In particular, the experimental methods for measuring the drag reduction effect of textured surfaces are introduced, which is extremely rare. The article concludes with a summary of existing problems and future directions in the research of biomimetic surface drag reduction technology. This Review can provide a reference for practical application and laboratory research of drag reduction in marine transportation, military weapons, aviation, and pipeline systems.

Experimental Investigations of the Turbulent Boundary Layer for Biomimetic Protrusive Surfaces Inspired by Pufferfish Skin: Effects of Spinal Density and Diameter

“…Research on surface microstructure drag reduction is no longer limited to continuous and neat ribs with two-dimensional cross sections but gradually becomes intermittent and bifurcated to seek a higher drag reduction rate . Furthermore, some bionic surfaces with three-dimensional raised structures have been found to have drag reduction potential and have been extensively studied . Protrusive surfaces are abundant in nature, in the form of undulating peaks, cone trees, cactus spikes, and small spines on fish skin, which indicate adaptability to realistic operating conditions.…”

“…6 Furthermore, some bionic surfaces with three-dimensional raised structures have been found to have drag reduction potential and have been extensively studied. 7 Protrusive surfaces are abundant in nature, in the form of undulating peaks, cone trees, cactus spikes, 8 and small spines on fish skin, which indicate adaptability to realistic operating conditions. It is reported that the protruding structure can raise the TBL and reduce the viscous drag, which is beneficial to reducing the drag.…”

Rheological Properties and Drag Reduction Performance of Puffer Epidermal Mucus

“…The mucus at the bottom is not easily lost even at high inflow velocities because of the obstruction of the puffer spines. Moreover, the drag reduction function of the puffer spines has been proven. − …”

Coupled Bionic Drag-Reducing Surface Covered by Conical Protrusions and Elastic Layer Inspired from Pufferfish Skin

“…The surface of marine organisms secretes mucus to cover the whole body, the rough skin of sharks is covered by the shield scale, and covering with an elastic-damping layer is a strategy for dolphins to combat water. The hydrodynamic advantages of the ribs on the shark's bionic drag reduction surface and the ribs embedded in the turbulent boundary layer (TBL) have been fully demonstrated, and their cross sections are regular ravines such as triangles or rectangles, 5 due to the diversion of ribs and the boosting effect of the similar vortex generator shield scales. However, the special structure of the groove also tends to accumulate fouling, leading to clogging and surface performance failure.…”