Effects of body elasticity on stability of underwater locomotion

Jing, Fangxu; Kanso, Eva

doi:10.1017/jfm.2011.450

Cited by 7 publications

(5 citation statements)

References 27 publications

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“…Note that the three-link swimmer was also used by Jing & Kanso to study the effect of body elasticity on the stability of the coast motion of fish (motion at constant speed). They found that elasticity of the body may lead to passive stabilization of the (otherwise unstable) coast motion, see [8,9]. The present model consisting of a single elliptic body is mostly similar to the system studied by Spagnolie et al (2010) both experimentally and numerically, see [10].…”

Section: Introductionsupporting

confidence: 61%

Stability of underwater periodic locomotion

Jing

Kanso

2013

Regul. Chaot. Dyn.

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Most aquatic vertebrates swim by lateral flapping of their bodies and caudal fins. While much effort has been devoted to understanding the flapping kinematics and its influence on the swimming efficiency, little is known about the stability (or lack of) of periodic swimming. It is believed that stability limits maneuverability and body designs/flapping motions that are adapted for stable swimming are not suitable for high maneuverability and vice versa. In this paper, we consider a simplified model of a planar elliptic body undergoing prescribed periodic heaving and pitching in potential flow. We show that periodic locomotion can be achieved due to the resulting hydrodynamic forces, and its value depends on several parameters including the aspect ratio of the body, the amplitudes and phases of the prescribed flapping. We obtain closed-form solutions for the locomotion and efficiency for small flapping amplitudes, and numerical results for finite flapping amplitudes. We then study the stability of the (finite amplitude flapping) periodic locomotion using Floquet theory. We find that stability depends nonlinearly on all parameters. Interesting trends of switching between stable and unstable motions emerge and evolve as we continuously vary the parameter values. This suggests that, for live organisms that control their flapping motion, maneuverability and stability need not be thought of as disjoint properties, rather the organism may manipulate its motion in favor of one or the other depending on the task at hand.

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Section: Introductionsupporting

confidence: 61%

Stability of underwater periodic locomotion

Jing

Kanso

2013

Regul. Chaot. Dyn.

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“…wheret andθ r are integration variables. Once θ c (t) is obtained, the position of C can be given by (14),…”

Section: Two-link Model Analysismentioning

confidence: 99%

“…Kanso et al [15] and Melli et al [18] gave a geometric formulation for swimming in a potential flow and calculated optimal strokes. Jing & Kanso [14] used this formulation to study the effects of elasticity and body configuration on the stability of passive locomotion.…”

Section: Introductionmentioning

confidence: 99%

Optimization of two- and three-link snakelike locomotion

Jing

Alben

2013

Phys. Rev. E

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We analyze two- and three-link planar snakelike locomotion and optimize the motion for efficiency. The locomoting system consists of two or three identical inextensible links connected via hinge joints, and the angles between the links are actuated as prescribed periodic functions of time. An essential feature of snake locomotion is frictional anisotropy: The forward, backward, and transverse coefficients of friction differ. The dynamics are studied analytically and numerically for small and large amplitudes of the internal angles. Efficiency is defined as the ratio between distance traveled and the energy expended within one period, i.e., the inverse of the cost of locomotion. The optimal set of coefficients of friction to maximize efficiency consists of a large backward coefficient of friction and a small transverse coefficient of friction, compared to the forward coefficient of friction. For the two-link case with a symmetrical motion, efficiency is maximized when the internal angle amplitude is approximately π/2 for a sufficiently large transverse coefficient. For the three-link case, the efficiency-maximizing paths are triangles in the parameter space of internal angles.

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“…where C d is defined as the resistance coefficient of the spoiler cylinder (C d is 1.11, according to the empirical value [34]), and D and L are respectively defined as the diameter and length of the spoiler cylinder. The work of the damping force generated by the spoiler cylinder in a cycle is given by Equation (5):…”

Section: Theoretical Analysismentioning

confidence: 99%

“…The resistance coefficient is a function of the Reynolds number [34]. The Reynolds number is related to the velocity, so the resistance coefficient is related to the speed.…”

Section: Simulation Verification Of the Value Of Resistance Coefficientmentioning

confidence: 99%

Study on the Critical Wind Speed of a Resonant Cavity Piezoelectric Energy Harvester Driven by Driving Wind Pressure

Xia

Liu

et al. 2019

Micromachines

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In order to solve the problem of continuous and stable power supply for vehicle sensors, a resonant cavity piezoelectric energy harvester driven by driving wind pressure was designed. The harvester has an effective working range of wind speed. According to the energy conservation law, the cut-in (initial) wind speed of the harvester was solved. The pressure distribution law of the elastic beam in the flow field was studied by the Fluent software package, and the results were loaded into a finite element model with a method of partition loading. The relationship between the wind speed and the maximum principal stress of the piezoelectric cantilever beam was analyzed, and the critical stress method was used to study the cut-out wind speed of the energy harvester. The results show that the cut-in wind speed of the piezoelectric energy harvester is 5.29 m/s, and the cut-out wind speed is 24 m/s. Finally, an experiment on the power generation performance of the energy harvester was carried out. The experimental results show that the cut-in and cut-out wind speeds of the piezoelectric energy harvester are 5 m/s and 24 m/s, respectively, and the best matching load is 60 kΩ. The average output power, generated by the harvester when the driving wind speed is 22 m/s, is 0.145 mW, and the corresponding power density is 1.2 mW/cm 3 .

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Effects of body elasticity on stability of underwater locomotion

Cited by 7 publications

References 27 publications

Stability of underwater periodic locomotion

Stability of underwater periodic locomotion

Optimization of two- and three-link snakelike locomotion

Study on the Critical Wind Speed of a Resonant Cavity Piezoelectric Energy Harvester Driven by Driving Wind Pressure

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