Jet flow in steadily swimming adult squid

  title={Jet flow in steadily swimming adult squid},
  author={Erik J. Anderson and Mark A. Grosenbaugh},
  journal={Journal of Experimental Biology},
  pages={1125 - 1146}
SUMMARY Although various hydrodynamic models have been used in past analyses of squid jet propulsion, no previous investigations have definitively determined the fluid structure of the jets of steadily swimming squid. In addition, few accurate measurements of jet velocity and other jet parameters in squid have been reported. We used digital particle imaging velocimetry (DPIV) to visualize the jet flow of adult long-finned squid Loligo pealei (mantle length, Lm=27.1±3.0 cm, mean ± s.d.) swimming… 

Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers

The detection of high propulsive efficiency in paralarvae is significant because it contradicts many studies that predict low propulsive Efficiency at intermediate Re for inertial forms of locomotion.


Squids in nature generate pulsed jet to be able to move by expelling high pressure water through funnel in a short period of time. In this study, unsteady jet flow of squids was investigated during

Hydrodynamic fin function of brief squid, Lolliguncula brevis

The results demonstrate the lateral fins are an integral component of the complex locomotive system of L. brevis, producing lift and thrust forces through different locomotive modes.

CFD Simulation of Effect of Vortex Ring for Squid Jet Propulsion And Expeiments on a Bionic Jet Propulsor

Using jet propulsion, squid can swim at high speed or at low speed with good maneuverability, which makes them quiet valuable to be studied for biomimetic purposes. Vortex rings usually occur in the

Aperture effects in squid jet propulsion

The behavior and kinematics of locomotion in 1 mm paralarvae of Dosidicus gigas, the smallest squid yet studied, are described and a theoretical model of jet propulsion scaled from the smallest (1 mm mantle length) to the largest (3 m) squid is explored.

Hydrodynamics of pulsed jetting in juvenile and adult brief squid Lolliguncula brevis: evidence of multiple jet `modes' and their implications for propulsive efficiency

From early juvenile through to adult life stages, L. brevis is capable of producing a diversity of vortex ring-based jet structures, ranging from efficient short pulses to high-force longer duration pulses, clear that squid have a locomotive repertoire far more complex than originally thought.

Dynamics of a squid-inspired swimmer in free swimming

Results of both escape jetting via a single deflation-coasting motion and long-distance swimming via repeated inflation-deflation cycles are presented, finding that the increase of the jet speed and oscillation frequency leads to higher swimming velocity.

Volumetric flow imaging reveals the importance of vortex ring formation in squid swimming tail-first and arms-first

Multi-propulsor squids produce complex 3D vortex wake flows while swimming arms-first and tail-first, as revealed by 3D jet/fin force and propulsive efficiency measurements.

Pulsed-jet propulsion of a squid-inspired swimmer at high Reynolds number

An inflation-deflation propulsion system inspired by the jet propulsion mechanism of squids and other cephalopods is proposed. The two-dimensional squid-like swimmer has a flexible mantle body with a

Drag force and jet propulsion investigation of a swimming squid

In this study, CAD model of a squid was obtained by taking computer tomography images of a real squid. The model later placed into a computational domain to calculate drag force and performance of

The mechanics of locomotion in the squid Loligo pealei: locomotory function and unsteady hydrodynamics of the jet and intramantle pressure.

The equations for squid propulsive efficiency reveal that the refill period of squid plays a greater role, and the jet period a lesser role, in the low whole-cycle efficiencies predicted in squid and similar jet-propelled organisms.

Hydrodynamics of locomotion in the squid Loligo pealei

Potential flow analysis, including unsteady effects, has been applied to live swimming squid, Loligo pealei. Squid were modelled as slender, axisymmetric bodies. High-speed video records, recorded at

The Forces Acting on Swimming Squid

Analysis of cine films and intramantle pressure records for squid Loligo opalescens Berry swimming in a tunnel respirometer provided estimates of all the forces acting in the horizontal and vertical planes for swimming speeds, suggesting a new rationale for ‘climb-and-glide’ swimming which reduces previous estimates of the gross cost of transport for squid under natural conditions by at least 35%, with no loss of speed.

Generation of a vortex chain in the wake of a Suhundulatory swimmer

An estimate of thrust and efficiency based for the first time on the flow in the wake of freely swimming rainbow trout is presented, required the reconstruction of the three-dimensional vortex pattern as well as a quantification of the flow velocities, both of which are missing in studies so far available.

Swimming mechanics and behavior of the shallow-water brief squid Lolliguncula brevis.

Negatively buoyant brief squid generated lift and/or improved stability by positioning the mantle and arms at high angles of attack, directing high-speed jets downwards (angles >50 degrees ) and using fin activity.

Aerobic respiratory costs of swimming in the negatively buoyant brief squid Lolliguncula brevis.

The results of this study indicate that, like aerial flyers, some negatively buoyant nekton have parabolic patterns of O(2) consumption rate/power as a function of speed and that certain shallow-water squid using considerable fin activity have swimming costs that are competitive with those of ecologically relevant fishes.

A hydrodynamic analysis of fish swimming speed: wake structure and locomotor force in slow and fast labriform swimmers.

Two hypotheses relating locomotor stability, maneuverability and the structure of the vortex wake are presented and a potential hydrodynamic trade-off between speed and maneuverability that arises as a geometric consequence of the orientation of vortex rings shed by the pectoral fins is proposed.

Jet Propulsion and the Giant Fibre Response of Loligo

In decapods possessing the giant fibre system, mantle, head retractors and funnel are provided with a nervous control mechanism especially adapted for ensuring that the compression chamber neither herniates nor leaks and is emptied of all its water in a single compression stroke.

The locomotory function of the fins in the squid Loligo pealei

Kinematic data of high spatial and temporal resolution, acquired from image sequences of adult long-finned squid, Loligo pealei, during steady swimming in a flume, revealed a role of fins at all swimming speeds by a transition from drag-based to lift-based thrust when fin wave speed dropped below swimming speed.

The boundary layer of swimming fish.

Inflected boundary layers, suggestive of incipient separation, were observed sporadically, but appeared to be stabilized at later phases of the undulatory cycle, which may be evidence of hydrodynamic sensing and response towards the optimization of swimming performance.