Plume of the Space Shuttle Atlantis after launch.

In hydrodynamics, a plume is a column of one fluid moving through another. Several effects control the motion of the fluid, including momentum, buoyancy and density difference. When momentum effects are more important than density differences and buoyancy effects the plume is usually described as a jet. Image File history File links Download high-resolution version (1539x2200, 222 KB) Summary Space Shuttle Atlantis launches at sunset. ... Image File history File links Download high-resolution version (1539x2200, 222 KB) Summary Space Shuttle Atlantis launches at sunset. ... Space Shuttle Orbiter Atlantis (NASA Orbiter Vehicle Designation: OV-104) is one of the fleet of space shuttles belonging to the U.S. National Aeronautics and Space Administration (NASA). ... Hydrodynamics is fluid dynamics applied to liquids, such as water, alcohol, oil, and blood. ...

Usually, as a plume moves away from its source it widens because of entrainment of the surrounding fluid at its edges. This usually causes a plume which has initially been 'momentum-dominated' to become 'buoyancy-dominated' (this transition is usually predicted by a dimensionless number called the Richardson number) Entrainment is the movement of one fluid by another. ... The Richardson number is named after Lewis Fry Richardson (1881 - 1953). ...

A further phenomenon of importance is whether a plume is in laminar flow or turbulent flow. Usually there is a transition from laminar to turbulent as the plume moves away from its source. This phenomenon can be clearly seen in the rising column of smoke from a cigarette.

Industrial air pollution plumes

Another phenomenon which can also be seen clearly in the flow of smoke from a cigarette is that the leading-edge of the flow, or the starting-plume, is quite often approximately in the shape of a ring-vortex (smoke ring). ^[1] Image File history File links AirPollutionSource. ... Image File history File links AirPollutionSource. ... Vortex created by the passage of an aircraft wing, revealed by coloured smoke A vortex (pl. ... Human blown smoke ring. ...

Plumes are of considerable importance in the dispersion of air pollution. A classic work on the subject of air pollution plumes is that by Gary Briggs. ^[2][3] Atmospheric dispersion modeling is performed with computer programs that use mathematical equations and algorithms to simulate how pollutants in the ambient atmosphere disperse in the atmosphere. ...

A thermal plume is one which is generated by gas rising from above heat source. The gas rises because thermal expansion makes warm gas less dense than the surrounding cooler gas. In physics, thermal expansion is the tendency of matter to increase in volume or pressure when heated. ...

In large scale atmospheric simulations, a nuclear explosion can be considered as a short duration thermal point source, which generates a characteristic mushroom-shaped thermal plume rising up into the stratosphere.

Download high resolution version (1180x1474, 162 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1180x1474, 162 KB) Wikipedia does not have an article with this exact name. ... The atomic bombing of Nagasaki, Japan on August 9, 1945 A mushroom cloud is a distinctive mushroom-shaped cloud of smoke, flame, or debris resulting from a very large explosion. ... Atmosphere diagram showing stratosphere. ...

Simple Plume Modelling

Quite simple modelling will enable many properties of fully developed turbulent plumes to be investigated. 1) It is usually sufficient to assume that the pressure gradient is set by the gradient far from the plume (this approximation is similar to the usual Boussinesq approximation) In fluid dynamics, the Boussinesq approximation is used in the field of buoyancy-driven flow. ...

2) The distribution of density and velocity across the plume are modelled either with simple Gaussian distributions or else are taken as uniform across the plume (the so-called 'top hat' model).

3) Mass entrainment velocity into the plume is given by a simple constant times the local velocity - this constant typically has a value of about 0,08 for vertical jets and 0.12 for vertical buoyant plumes. For bent-over plumes, the entrainment coefficient is about 0.6.

4) Conservations equations for mass flux (including entrainment) and momentum flux(allowing for buoyancy) then give sufficient information for many purposes.

For a simple rising plume these equations predict that the plume will widen at a constant half-angle of about 6 to 15 degrees

A top-hat model of a circular plume entraining in a fluid of the same density ρ is as follows:-

The Momentum M of the flow is conserved so that

Aρv² = M is constant

The mass flux J varies, due to entrainment at the edge of the plume, as

dJ / dx = dAρv / dx = krρv

where k is an entrainment constant, r is the radius of the plume at distance x, and A is its cross-sectional area.

This shows that the mean velocity v falls inversely as the radius rises, and the plume grows at a constant angle dr/dx= k'

Large Natural Convection Plume.

Image File history File links Metadata Size of this preview: 720 × 600 pixelsFull resolution (898 × 748 pixel, file size: 41 KB, MIME type: image/jpeg) Large Natural Convection Plume, as effect of combustion of excess non-useable gases behind oilfield, Darkhuien, Abadan, Iran. ... Image File history File links Metadata Size of this preview: 720 × 600 pixelsFull resolution (898 × 748 pixel, file size: 41 KB, MIME type: image/jpeg) Large Natural Convection Plume, as effect of combustion of excess non-useable gases behind oilfield, Darkhuien, Abadan, Iran. ...

See also

• Atmospheric dispersion modeling
• Air pollution dispersion modeling books
• Air pollution dispersion terminology

Atmospheric dispersion modeling is performed with computer programs that use mathematical equations and algorithms to simulate how pollutants in the ambient atmosphere disperse in the atmosphere. ... The information listed below for each of the air pollution dispersion modeling books includes the author(s), the publication date, the title, the edition, by whom published, and the ISBN or ISSN where available. ... Air pollution dispersion terminology describes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling. ...

Reference

1. ^ Turner, J. S. (1962). The Starting Plume in Neutral Surroundings, J. Fluid Mech. vol 13, pp356-368
2. ^ Briggs, Gary A. (1975). Plume Rise Predictions, Chapter 3 in Lectures on Air Pollution and Environmental Impact Analysis, Duanne A. Haugen, editor, Amer. Met. Soc.
3. ^ Beychok, Milton R. (2005). Fundamentals Of Stack Gas Dispersion, 4th Edition, author-published. ISBN 0-9644588-0-2.