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 ...
, convective mixing is the vertical transport of a
fluid
In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...
and its properties. In many important
ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...
and
atmospheric
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere ...
phenomena,
convection
Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...
is driven by
density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...
differences in the
fluid
In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...
, e.g. the sinking of cold, dense
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
in polar regions of the world's oceans; and the rising of warm, less-dense air during the formation of
cumulonimbus cloud
Cumulonimbus () is a dense, towering, vertical cloud, typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful buoyant air currents. Above the lower portions of the cumulonimbus the water ...
s and
hurricane
A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its ...
s.
See also
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Atmospheric convection
Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks.
This process is driven by parcel-environment instability, meaning that a "par ...
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Bénard cells
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Churchill–Bernstein equation
In convective heat transfer, the Churchill–Bernstein equation is used to estimate the surface averaged Nusselt number for a cylinder in cross flow at various velocities. The need for the equation arises from the inability to solve the Navier� ...
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Double diffusive convection
Double diffusive convection is a fluid dynamics phenomenon that describes a form of convection driven by two different density gradients, which have different rates of diffusion.
Convection in fluids is driven by density variations within them u ...
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Heat transfer
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...
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Heat conduction
Thermal conduction is the diffusion of thermal energy (heat) within one material or between materials in contact. The higher temperature object has molecules with more kinetic energy; collisions between molecules distributes this kinetic energy u ...
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Thermal radiation
Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The emission of energy arises from a combination of electro ...
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Heat pipe
A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces.
At the hot interface of a heat pipe, a volatile liquid in contact with a thermally conductive solid surface turns into a vapor ...
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Laser-heated pedestal growth
Laser-heated pedestal growth (LHPG) or laser floating zone (LFZ) is a crystal growth technique. A narrow region of a crystal is melted with a powerful Carbon-dioxide laser, CO2 or Nd:YAG laser. The laser and hence the zone melting, floating zone, i ...
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Nusselt number
In thermal fluid dynamics, the Nusselt number (, after Wilhelm Nusselt) is the ratio of total heat transfer to conductive heat transfer at a boundary in a fluid. Total heat transfer combines conduction and convection. Convection includes both ...
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Thermomagnetic convection Ferrofluids can be used to transfer heat, since heat and mass transport in such magnetic fluids can be controlled using an external magnetic field.
B. A. Finlayson first explained in 1970 (in his paper "Convective instability of ferromagnetic fl ...
References
Notes
Further reading
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{{fluiddynamics-stub
Convection