In fluid dynamics, the fluid flow is often decomposed into a '''mean flow''' and deviations from the mean. The averaging can be done either in space or in time, or by ensemble averaging.

==Example== Calculation of the mean flow may often be as simple as the mathematical mean: simply add up the given flow rates and then divide the final figure by the number of initial readings.

For example, given two discharges (''Q'') of 3&nbsp;m³/s and 5&nbsp;m³/s, we can use these flow rates ''Q'' to calculate the mean flow rate ''Q''<sub>mean</sub>. Which in this case is ''Q''<sub>mean</sub>&nbsp;=&nbsp;4&nbsp;m³/s.

==See also== * Generalized Lagrangian mean

==References== * {{Citation | title=Wave interactions and fluid flows | first=Alex D. D. | last=Craik | publisher=Cambridge University Press | year=1988 | isbn=978-0-521-36829-2 }} * {{Citation | title=A first course in turbulence | first1=Hendrik | last1=Tennekes | author1-link=Hendrik Tennekes | first2=John L. | last2=Lumley | author2-link=John L. Lumley | publisher=MIT Press | year=1972 | isbn=978-0-262-20019-6 }}

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Category:Fluid dynamics