# Kelvin wake pattern - Wikipedia

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2023-09-14 13:30:02

Waterfowl and boats moving across the surface of water produce a wake pattern, first explained mathematically by Lord Kelvin and known today as the Kelvin wake pattern.[1]

This pattern consists of two wake lines that form the arms of a chevron, V, with the source of the wake at the vertex of the V. For sufficiently slow motion, each wake line is offset from the path of the wake source by around arcsin(1/3) = 19.47° and is made up of feathery wavelets angled at roughly 53° to the path.

The inside of the V (of total opening 39° as indicated above) is filled with transverse curved waves, each of which resembles an arc of a circle centered at a point lying on the path at a distance twice that of the arc to the wake source. This part of the pattern is independent of the speed and size of the wake source over a significant range of values.

However, at higher speeds (specifically, at large Froude number) other parts of the pattern come into play. At the tips of the transverse wave arcs their crests turn around and continue inside the V cone and towards the source, forming an overlapping pattern of narrower waves directed outside of the cone. As the source's speed increases, these shorter waves begin to dominate and form a second V within the pattern, which grows narrower as the increased speed of the source emphasizes the shorter waves that are closer to the source's path.[2]