Lord Kelvin's isotropic helicoid
Abstract
Nearly 150 years ago, Lord Kelvin proposed the isotropic helicoid, a particle with isotropic yet chiral interactions with a fluid, so that translation couples to rotation. An implementation of his design fabricated with a three-dimensional printer is found experimentally to have no detectable translation-rotation coupling, although the particle point-group symmetry allows this coupling. We explain these results by demonstrating that in Stokes flow, the chiral coupling of such isotropic helicoids made out of non-chiral vanes is due only to hydrodynamic interactions between these vanes. Therefore it is small. In summary, Kelvin's predicted isotropic helicoid exists, but only as a weak breaking of a symmetry of non-interacting vanes in Stokes flow.
Cite
@article{arxiv.2006.08282,
title = {Lord Kelvin's isotropic helicoid},
author = {Darci Collins and Rami J. Hamati and Fabien Candelier and Kristian Gustavsson and Bernhard Mehlig and Greg A. Voth},
journal= {arXiv preprint arXiv:2006.08282},
year = {2021}
}
Comments
12 pages, 5 figures, final version