A bow wave is the

wave In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (res ...

that forms at the bow of a ship when it moves through the water. As the bow wave spreads out, it defines the outer limits of a ship's wake. A large bow wave slows the ship down, is a risk to smaller boats, and in a harbor can damage shore facilities and moored ships. Therefore,

ship hull A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, d ...

s are generally designed to produce as small a bow wave as possible.

Description

The size of the bow wave is a function of the speed of the ship, its

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a vesse ...

surface wave In physics, a surface wave is a mechanical wave that propagates along the Interface (chemistry), interface between differing media. A common example is gravity waves along the surface of liquids, such as ocean waves. Gravity waves can also occu ...

s, water depth, and the shape of the bow. A ship with a large

and a blunt bow will produce a large wave, and ships that

plane Plane(s) most often refers to: * Aero- or airplane, a powered, fixed-wing aircraft * Plane (geometry), a flat, 2-dimensional surface Plane or planes may also refer to: Biology * Plane (tree) or ''Platanus'', wetland native plant * ''Planes' ...

over the water surface will create smaller bow waves. Bow wave patterns are studied in the field of

computational fluid dynamics Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate th ...

. The bow wave carries energy away from the ship at the expense of its kinetic energy—it slows the ship. A major goal of

naval architecture Naval architecture, or naval engineering, is an engineering discipline incorporating elements of mechanical, electrical, electronic, software and safety engineering as applied to the engineering design process, shipbuilding, maintenance, and o ...

is therefore to reduce the size of the bow wave and improve the ship's fuel economy. Modern ships are commonly fitted with a

bulbous bow A bulbous bow is a protruding bulb at the bow (or front) of a ship just below the waterline. The bulb modifies the way the water flows around the hull, reducing drag and thus increasing speed, range, fuel efficiency, and stability. Large ships w ...

to achieve this. A bow wave forms at the head of a swimmer moving through water. The trough of this

is near the mouth of the swimmer and helps the swimmer to inhale air to breathe just by turning their head. A similar thing occurs when an airplane travels at the speed of sound. The overlapping wave crests disrupt the flow of air over and under the wings. Just as a boat can easily travel faster than the wave it produces, an airplane with sufficient power can travel faster than the speed of sound (supersonic).

References

External links

Bow waves - Feynman Lectures on Physics
Naval architecture Fluid dynamics Water waves {{navy-stub

Description

See also

References

External links