Self-consistent theory of capillary-gravity-wave generation by small moving objects.
We investigate theoretically the onset of capillary-gravity waves created by a small object moving at the water-air interface. It is well established that, for straight uniform motion, no steady waves appear at velocities below the minimum phase velocity c(min)=23 cm/s. At higher velocities, the emission of capillary-gravity waves creates an additional drag force. The behavior of this force near the critical velocity is still poorly understood. A linear-response theory where the object is replaced by an effective pressure source predicts a singular behavior for the wave drag. However, experimental data tend to indicate a more continuous transition. In this paper, we show that a proper treatment of the flow equations around the obstacle can regularize wave emission, even in the linear wave approximation, thereby ensuring a continuous behavior of the drag force.
Chepelianskii
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AD
Laboratoire de Physique des Solides, Université Paris-Sud-CNRS, UMR 8502, Orsay, France.
Schindler
M
M
Chevy
F
F
Raphaël
E
E