Movement
Usually, as a plume moves away from its source, it widens because of entrainment of the surrounding fluid at its edges. Plume shapes can be influenced by flow in the ambient fluid (for example, if local wind blowing in the same direction as the plume results in a co-flowing jet). This usually causes a plume which has initially been 'buoyancy-dominated' to become 'momentum-dominated' (this transition is usually predicted by a dimensionless number called the Richardson number).
Read more about this topic: Plume (hydrodynamics)
Famous quotes containing the word movement:
“There is no example in history of a revolutionary movement involving such gigantic masses being so bloodless.”
—Leon Trotsky (1879–1940)
“Every little movement has a meaning all its own.”
—Otto Harbach (1873–1963)
“Christianity was only a very strong and singularly well-timed Salvation Army movement that happened to receive help from an unusual and highly dramatic incident. It was a Puritan reaction in an age when, no doubt, a Puritan reaction was much wanted; but like all sudden violent reactions, it soon wanted reacting against.”
—Samuel Butler (1835–1902)