ESPCI web site
Waves and wakes at different scales
Simply by looking at a duck swimming in a pond or a cargo ship moving on a calm sea, one can clearly tell that there is something common about their wake. Indeed, they both display a familiar V-shaped pattern which only differ from one another by their dimensions. In 1887, Lord Kelvin was able to provide a theory to explain the ship-wave pattern. His most popular achievement was to prove that the wake created by a disturbance moving at a uniform pace is always delimited by a straight wedge with half-angle 19.5 degrees, independent of the velocity of the disturbance. Recently, Kelvin’s century old and well accepted theory was challenged, by that drawing the attention of the fluid dynamics community…
