Understanding of remora's “hitchhiking” behaviour from a hydrodynamic point of view

Abstract

Symbiotic relationships have developed through natural evolution. For example, that of the remora fish attached to the body of a shark. From the remora’s perspective, this could be associated to an increased hydrodynamic efficiency in swimming and this needs to be investigated. To understand the remora's swimming strategy in the attachment state, a systematic study has been conducted using the commercial Computational Fluid Dynamics (CFD) software, STAR-CCM + to analyse and compare the resistance characteristics of the remora in attached swimming conditions. Two fundamental questions are addressed: what is the effect of the developed boundary layer flow and the effect of the adverse pressure gradient on the remora’s hydrodynamic characteristics? According to the results, the resistance of the remora can generally be halved when attached. Besides, the results have also demonstrated that the drag reduction rate increases with the developed boundary layer thickness and can be estimated using the boundary layer thickness ratio and velocity deficit. The paper demonstrates that the most frequent attachment locations are also the areas that provide the maximum drag reduction rate.

Advanced Bionic Attachment Equipment Inspired by the Attachment Performance of Aquatic Organisms: A Review

“…For example, the remora can attach to various fast-moving host organisms and marine vessels, and hitch firmly and reversibly with the help of its unique dorsal suction cup [ 62 , 63 , 64 , 65 , 66 ] ( Figure 1 d). The sucker of the remora is mainly composed of the lip, compartment, and comb-tooth lamella.…”

Hydrodynamics of a Remora-Inspired Autonomous Underwater Vehicle Approaching and Docking to a Benchmark Submarine

“…This section presents an investigation into the hydrodynamic performance of the remorainspired AUVs. Based on a prior hydrodynamics study of the remora [10], the inspiration for the hull design was drawn from the posture of the remora fish docking on the shark. Two types of simulations were conducted in this section.…”

“…Additionally, it should This preprint research paper has not been peer reviewed. Electronic copy available at: https://ssrn.com/abstract=4453333 P r e p r i n t n o t p e e r r e v i e w e d Hydrodynamics of a remora-inspired autonomous underwater vehicle approaching and docking to a benchmark submarine be noted that due to the incoming flow being blocked by the dorsal fin and shark body and adverse pressure gradients generated behind them, a forward thrust was provided for the remora fish [10].…”

Adopting Physical Artificial Intelligence in Soft Aerial Robots

“…Animals also perch and rest as a form of energy saving method [118]. Finally, as often seen in plants [154], insects [155,156], and other animals [157][158][159], hitchhiking or piggybacking is highly effective strategy in low energy locomotion. Animals and plants, by attaching themselves onto a moving object, such as adhesion onto animal fur/skin or sitting inside a mother's pouch as seen with marsupials, they can travel in multi-mediums (air, water, and land) whiles aided to minimize the use of energy.…”