The Study of Drag Reduction on Ships Inspired by Simplified Shark Skin Imitation

Abstract

The skin of a fast swimming shark reveals riblet structures that help reduce the shark's skin friction drag, enhancing its efficiency and speed while moving in the water. Inspired by the structure of the shark skin denticles, our team has carried out a study as an effort in improving the hydrodynamic design of marine vessels through hull design modification which was inspired by this riblet structure of shark skin denticle. Our study covers on macroscaled design modification. This is an attempt to propose an alternative for a better economical and practical modification to obtain a more optimum cruising characteristics for marine vessels. The models used for this study are constructed using computer-aided design (CAD) software, and computational fluid dynamic (CFD) simulations are then carried out to predict the effectiveness of the hydrodynamic effects of the biomimetic shark skins on those models. Interestingly, the numerical calculated results obtained show that the presence of biomimetic shark skin implemented on the vessels give about 3.75% reduction of drag coefficient as well as reducing up to 3.89% in drag force experienced by the vessels. Theoretically, as force drag can be reduced, it can lead to a more efficient vessel with a better cruising speed. This will give better impact to shipping or marine industries around the world. However, it can be suggested that an experimental procedure is best to be conducted to verify the numerical result that has been obtained for further improvement on this research.

Nature-Inspired Structures Applied in Heat Transfer Enhancement and Drag Reduction

“…Inspired by shark skins, the grooves have been proposed, which could change the flow pattern in the turbulent boundary layer and reduce the viscous resistance of the fluid [68,69]. Grooves with triangular, trapezoidal, semicircular, rectangular, blade and sinusoidal sections have been designed [70][71][72][73]. The drag reduction rates of four textured surfaces with V-shaped, saw tooth, rectangular and semi-circular sections were examined.…”

Evaluation of an Antifouling Surface Inspired by Malaysian Sharks <i>Negaprion</i> <i>Brevirostris</i> and <i>Carcharhinus Leucas</i> Riblets

“…All sharks are the type of fish and belong to a class called Chondorichthyes. Shark skin made up of dermal denticle which is like its teeth known as minicule placoid scales causing the skin surface of shark rough and harsh [5]. Vitrodentine are enamel that covers the denticles, having pulp and cavity similar with teeth where these tooth-like structures cover the sharks completely giving the shark the advantage during swimming [6].…”

“…Other than that, the denticles also act as a barrier protection to the shark [10]. As denticles are closely spaced together forming grooves, these closely spaced channels seem to help in reducing drag during swimming as drag is reduced by inhibiting eddies from in contact with the surface of a moving body [5]. To breathe and move underwater, gills and fins have help sharks a lot in this breath mechanism and must constantly swimming, then shark only swim forward due to its pectoral fins that cannot be bent upward [10].…”

Laser Powder Bed Fusion of a Topology Optimized and Surface Textured Rudder Bulb with Lightweight and Drag-Reducing Design

“…Al-alloys are commonly employed for aerospace and automotive applications requiring lightweight design, where the desired mechanical properties rely on the careful selection of the process parameters [11]. Fluid dynamic behavior can be involved in the design and particularly on surface interaction [10,[12][13][14][15][16][17][18]. As geometrical features can be manufactured directly during the production run of the component, a new generation of products can be obtained, equipped with small-size surface features.…”