Wave drag on a submerged sphere

Adrien Benusiglio (1, 2) , Frédéric Chevy (3) , Élie Raphaël (4) , Christophe Clanet (1, 2)

1 LadHyX - Laboratoire d'hydrodynamique
2 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
3 LKB (Jussieu) - Laboratoire Kastler Brossel
4 LPCT - Laboratoire de Physico-Chimie Théorique

We measure the wave drag acting on fully submerged spheres as a function of their depth and velocity, with an apparatus that measures only the component of the drag due to the proximity of the free surface. We observe that close to the surface the wave drag is of the order of the hydrodynamic drag. In our range of study, the measured force is more than one order smaller than predictions based on linear response. In order to investigate this discrepancy, we measure the amplitude of the waves at the origin of the wave drag, comparing the measurement with a theoretical model. The model captures the measurements at "large depth" but the wave's amplitude saturates at "small depth," an effect that partially accounts for the difference between the predicted and measured wave drag. (C) 2015 AIP Publishing LLC.

Domains: Physics [physics]; Mechanics [physics]; Fluid mechanics [physics.class-ph]

Adrien Benusiglio, Frédéric Chevy, Élie Raphaël, Christophe Clanet. Wave drag on a submerged sphere. Physics of Fluids, 2015, 27 (7), pp.072101. ⟨10.1063/1.4923454⟩. ⟨hal-01187717⟩