Inertial Effects in Fluid Locomotion

Steve Childress Professor Courant Institute of Mathematical SciencesNew York UniversityNew York, NY Inertial effects emerge in fluid locomotion as the Reynolds number reaches the range 1-10. The transition to flapping flight in a small mollusc suggests a bifurcation to thrust production at a finite Reynolds number. We describe a simple table-top experiment where this bifurcation could be observed. In order to study models at arbitrary Reynolds number we revisit the classic problem of swimming of a sheet, studied by G.I. Taylor in Stokes flow. At finite and large Reynold number Taylor's result is modified. The known results are reexamined for large Reynolds number using boundary-layer theory, and the nature of the expansions is clarified for wave-like motions of the sheet. We apply this approach to recoil swimming, a mechanism of locomotion that is known to work in a perfect fluid, thus extending the theory to a slightly viscous fluid.

Location: Seaver Science Library (SSL) - , Rm 150

Audiences: Everyone Is Invited

Contact: April Mundy