Analytic Modeling of a Size-Changing Swimmer

Weymouth, Gabriel; Giorgio-Serchi, Francesco

doi:10.1007/978-3-030-55594-8_48

Cited by 5 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Taking into account the fact that with these parameters a is also enhanced by the wall (see figure 13), these appear to be the cases in which the wall plays a purely positive role in the start maneuver. A comparison between cases with different values of µ shows significant difference in terms of P. It suggests that in addition to inertia effect [32,33], at the Reynolds numbers considered in this study viscosity also plays an important role in determining the power expenditure. When the viscosity is low (µ = 0.0002), within certain ranges of L 0 the presence of the wall can reduce P, especially when ϕ = π.…”

Section: Parametric Effectsmentioning

confidence: 69%

Wall effect on the start maneuver of a jet swimmer

Zhu

2023

Bioinspir. Biomim.

View full text Add to dashboard Cite

Inspired by aquatic creatures such as squid, the novel propulsion method based on pulsed jetting is a promising way to achieve high speed and high maneuverability for soft-body robots. Since these robots are often designed to operate in confined space with complicated boundary conditions, it is critical to understand their dynamics in the vicinity of solid boundaries. In this study we numerically examine the start maneuver of an idealized jet swimmer near a wall. Our simulations illustrate three important mechanisms: 1) Due to the blocking effect of the wall the pressure inside the body is affected so that the forward acceleration is increased during deflation and decreased during inflation; 2) The wall affects the internal flow so that the momentum flux at the nozzle and subsequently the thrust generation during the jetting phase are slightly increased; 3) the wall affects the wake so that the refilling phase is influenced, leading to a scenario in which part of the energy expended during jetting is recovered during refilling to increase forward acceleration and reduce power expenditure. In general, the second mechanism is weaker than the other two. The exact effects of these mechanisms depend on physical parameters such as the initial phase of the body deformation, the distance between the swimming body and the wall, and the Reynolds number.

show abstract

Section: Parametric Effectsmentioning

confidence: 69%

Wall effect on the start maneuver of a jet swimmer

Zhu

2023

Bioinspir. Biomim.

View full text Add to dashboard Cite

show abstract

“…Most importantly, an accurate study of the manoeuvrability of mass-varying systems needs to be undertaken in order to accurately characterize the dynamics of this class of vehicles [28], [29]. Indeed, the variation of mass and added-mass [30] of this vehicle during a turning manoeuver significantly affects the turning moment and prevents the traditional dynamics equation employed for other thrust-vectoring systems to be employed here. From a design perspective, the most significant improvement needed is achievement of higher and more uniform forward speeds and construction of a variant of the robot independent of the shore-based power source and control logic.…”

Section: Discussionmentioning

confidence: 99%

Manoeuvring of an aquatic soft robot using thrust-vectoring

Wang

Lidtke

Giorgio-Serchi

et al. 2019

2019 2nd IEEE International Conference on Soft Robotics (RoboSoft)

Self Cite

View full text Add to dashboard Cite

Capability of a pulsed-jetting, aquatic soft robot to perform turning manoeuvres by means of a steerable nozzle is investigated experimentally for the first time. Actuation of this robot is based on the periodic conversion of slowly-charged elastic potential energy into fluid kinetic energy, giving rise to a cyclic pulsed-jet resembling the one observed in cephalopods. A steerable nozzle enables the fluid jet to be deflected away from the vehicle axis, thus providing the robot with the unique ability to manoeuvre using thrust-vectoring. This actuation scheme is shown to offer a high degree of control authority when starting from rest, yielding turning radii of the order of half of the body length of the vehicle. The most significant factor affecting efficiency of the turn has been identified to be the fluid momentum losses in the deflected nozzle. This leads, given the current nozzle design, to a distinct optimum nozzle angle of 35 • .

show abstract

“…In this work an analytical expression of the added-mass variation term has been formulated. Similar analyses have been conducted with respect to a self-propelled swimmer, in which the effects of the inertias of outside fluid and internal fluid have been incorporated into the model [57].…”

Section: Added-mass Effectmentioning

confidence: 99%

Physics and applications of squid-inspired jetting

Zhu

Xiao

2022

Bioinspir. Biomim.

View full text Add to dashboard Cite

In the aquatic world jet propulsion is a highly successful locomotion method utilized by a variety of species. Among them cephalopods such as squids excel in their ability for high-speed swimming. This mechanism inspires the development of underwater locomotion techniques which are particularly useful in soft-bodied robots. In this overview we summarize existing studies on this topic, ranging from investigations on the underlying physics to the creation of mechanical systems utilizing this locomotion mode. Research directions that worth future investigation are also discussed.

show abstract

Analytic Modeling of a Size-Changing Swimmer

Cited by 5 publications

References 15 publications

Wall effect on the start maneuver of a jet swimmer

Wall effect on the start maneuver of a jet swimmer

Manoeuvring of an aquatic soft robot using thrust-vectoring

Physics and applications of squid-inspired jetting

Contact Info

Product

Resources

About