In
fluid dynamics
In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in motion ...
, wave–current interaction is the interaction between
surface gravity waves and a
mean flow. The interaction implies an exchange of energy, so after the start of the interaction both the waves and the mean flow are affected.
For depth-
integrated and
phase
Phase or phases may refer to:
Science
*State of matter, or phase, one of the distinct forms in which matter can exist
*Phase (matter), a region of space throughout which all physical properties are essentially uniform
*Phase space, a mathematica ...
-
average
In colloquial, ordinary language, an average is a single number or value that best represents a set of data. The type of average taken as most typically representative of a list of numbers is the arithmetic mean the sum of the numbers divided by ...
d flows, the quantity of primary importance for the
dynamics of the interaction is the wave
radiation stress tensor.
Wave–current interaction is also one of the possible mechanisms for the occurrence of
rogue wave A rogue wave is an abnormally large ocean wave.
Rogue wave may also refer to:
* Optical rogue waves, are rare pulses of light analogous to rogue or freak ocean waves.
* Rogue Wave Software, a software company
* Rogue Wave (band), an American in ...
s, such as in the
Agulhas Current. When a
wave group
In physics, a wave packet (also known as a wave train or wave group) is a short burst of localized wave action that travels as a unit, outlined by an envelope. A wave packet can be analyzed into, or can be synthesized from, a potentially-infini ...
encounters an opposing current, the waves in the group may pile up on top of each other which will propagate into a rogue wave.
Classification
identifies five major sub-classes within wave–current interaction:
* interaction of waves with a large-scale current
field
Field may refer to:
Expanses of open ground
* Field (agriculture), an area of land used for agricultural purposes
* Airfield, an aerodrome that lacks the infrastructure of an airport
* Battlefield
* Lawn, an area of mowed grass
* Meadow, a grass ...
, with slow – as compared to the
wavelength
In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats.
In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...
–
two-dimensional
A two-dimensional space is a mathematical space with two dimensions, meaning points have two degrees of freedom: their locations can be locally described with two coordinates or they can move in two independent directions. Common two-dimension ...
horizontal variations of the current fields;
* interaction of waves with small-scale current changes (in contrast with the case above), where the horizontal current varies suddenly, over a
length scale
In physics, length scale is a particular length or distance determined with the precision of at most a few orders of magnitude. The concept of length scale is particularly important because physical phenomena of different length scales cannot af ...
comparable with the wavelength;
* the combined wave–current motion for currents varying (strongly) with depth below the
free surface
In physics, a free surface is the surface of a fluid that is subject to zero parallel shear stress,
such as the interface between two homogeneous fluids.
An example of two such homogeneous fluids would be a body of water (liquid) and the air in ...
;
* interaction of waves with
turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disruption between ...
; and
* interaction of ship waves and currents, such as in the ship's
wake.
See also
*
generalized Lagrangian mean
*
rip current
A rip current (or just rip) is a specific type of water current that can occur near beaches where waves break. A rip is a strong, localized, and narrow current of water that moves directly away from the shore by cutting through the lines of bre ...
Footnotes
References
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{{DEFAULTSORT:Wave-current interaction
Physical oceanography
Water waves