From AMS Glossary
Revision as of 18:54, 25 April 2012 by Perlwikibot
An average taken over many different flow realizations that have the same initial and boundary conditions.
In the limit of the sample size going to infinity, the ensemble average approaches the ensemble mean and may be a function of both time and position. When the flow is steady and homogeneous, the ensemble, space, and time means are equal.
Hinze, J. O. 1975. Turbulence. 2d ed., McGraw–Hill, . p. 5.