Experimental Dispersion Relation of Surface Waves Along a Torus of Fluid

Filip Novkoski (1) , Eric Falcon (1) , Chi-Tuong Pham (2, 3)

1 MSC - Matière et Systèmes Complexes
2 LISN - Laboratoire Interdisciplinaire des Sciences du Numérique
3 COMET - COuplages Multiphysiques Et Transferts - LISN

We report the observation of gravity-capillary waves on a torus of fluid. By means of an original technique, a stable torus is achieved by depositing water on a superhydrophobic groove with a shallow wedge-shaped channel running along its perimeter. Using a spatio-temporal optical measurement, we report the full dispersion relation of azimuthal waves propagating along the inner and outer torus borders, highlighting several branches modeled as varicose, sinuous and sloshing modes. Standing azimuthal waves are also studied leading to polygon-like patterns arising on the two torus borders with a number of sides different when a tunable decoupling of the two interfaces occurs. The quantized nature of the dispersion relation is also evidenced.

Mots clés: Experiments; Torus of fluid; Azymuthal waves; Gravity-capillary waves; Dispersion relation; Polygonal patterns; Toroidal droplets

Domaines: Dynamique des Fluides [physics.flu-dyn]; Formation de Structures et Solitons [nlin.PS]; Mécanique des fluides [physics.class-ph]

Filip Novkoski, Eric Falcon, Chi-Tuong Pham. Experimental Dispersion Relation of Surface Waves Along a Torus of Fluid. Physical Review Letters, 2021, 127, pp.144504. ⟨10.1103/PhysRevLett.127.144504⟩. ⟨hal-03321055⟩