Abstract
Sea snakes propel themselves by lateral deformation waves moving backwards along their bodies faster than they swim. In contrast to typical anguilliform swimmers, however, their swimming is characterized by exaggerated torsional waves that lead the lateral ones. The effect of torsional waves on hydrodynamic forces generated by an anguilliform swimmer is the subject matter of this study. The forces, and the power needed to sustain them, are found analytically using the framework of the slender (elongated) body theory. It is shown that combinations of torsional waves and angle of attack can generate both thrust and lift, whereas combinations of torsional and lateral waves can generate lift of the same magnitude as thrust. Generation of lift comes at a price of increasing tail amplitude, but otherwise carries practically no energetic penalty.
Highlights
Sea snakes have flattened bodies with no fins, and they propel themselves by lateral deformation waves moving backwards along their bodies faster than they swim—as a typical eellike swimmer does [1]
Can it be that the torsional waves come to balance the swimming snake against gravity? To answer this question, one will need an estimate of hydrodynamic forces acting on an anguilliform swimmer propelling itself by a combination of lateral and torsional waves—these forces are the subject matter of this study
The 2 coherence of the present results within the ideal fluid approximation is furnished in the electronic supplementary material by comparison with numerical simulations based on the vortex lattice method
Summary
Sea snakes have flattened bodies with no fins, and they propel themselves by lateral deformation waves moving backwards along their bodies faster than they swim—as a typical eellike (anguilliform) swimmer does [1]. The 2 coherence of the present results within the ideal fluid approximation is furnished in the electronic supplementary material by comparison with numerical simulations based on the vortex lattice method. An indication of their viability is furnished in Appendix I by comparison with observations of a swimming yellow-bellied sea snake Hydrophis platurus [1].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
