• Featured in Physics
  • Editors' Suggestion
  • Rapid Communication

Characteristics of swimming shelled Antarctic pteropods (Limacina helicina antarctica) at intermediate Reynolds number regime

Mohammad Mohaghar, Deepak Adhikari, and Donald R. Webster
Phys. Rev. Fluids 4, 111101(R) – Published 15 November 2019
Physics logo See Focus story: Video—Swimming Snails Use Insect-like Flapping

Abstract

The swimming characteristics achieved by flapping wings, translating motion, and shell pitching are studied from observations of shelled Antarctic pteropods (aquatic snails nicknamed “sea butterflies”). These pteropods (Limacina helicina antarctica) swim with a pair of parapodia (or “wings”) via a unique flapping propulsion mechanism that incorporates similar techniques as observed in small flying insects. The geometric scaling of the wing span (L), wing chord (c), and minor shell diameter (d) with respect to the major shell diameter (D) reveal geometric similitude. Thus, the major shell diameter (D) is the only length scale required to describe the size of the pteropods. The motion of swimming pteropods is characterized using flapping, translational, and rotational Reynolds numbers (i.e., Ref, ReU, and ReΩ). A critical value of the flapping Reynolds number, Ref=35, is found for the onset of translating and pitching locomotion. Finally, the relationship is obtained for the Strouhal number (StA=fA/U) for the pteropods using the geometric scalings and the translational and flapping Reynolds numbers. The Strouhal number is found to be between 0.2 and 0.4, which indicates general agreement with other oscillating organisms moving with high propulsion efficiency.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 12 June 2019

DOI:https://doi.org/10.1103/PhysRevFluids.4.111101

©2019 American Physical Society

Physics Subject Headings (PhySH)

Fluid DynamicsPhysics of Living Systems

Focus

Key Image

Video—Swimming Snails Use Insect-like Flapping

Published 15 November 2019

The unusual wing flapping of submerged “sea butterflies” is similar to that of birds and insects and may provide signs of climate stress.

See more in Physics

Authors & Affiliations

Mohammad Mohaghar, Deepak Adhikari, and Donald R. Webster*

  • School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Drive, Atlanta, Georgia 30332, USA

  • *dwebster@ce.gatech.edu

Article Text (Subscription Required)

Click to Expand

Multimedia (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 4, Iss. 11 — November 2019

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Fluids

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×