Reynolds averaging
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  Where <math>T</math> is a long enough time to average out the  +  Where <math>T</math> is a long enough time to average out the fluctuations in <math>\Phi</math>. 
  Reynolds averaging is often used in fluid dynamics to separate turbulent fluctuations from the meanflow. The term  +  Reynolds averaging is often used in fluid dynamics to separate turbulent fluctuations from the meanflow. The term Reynolds averaging originates from [[Osborne Reynolds]], who was the first to use this type of averaging in fluid dynamics. 
Latest revision as of 09:59, 7 September 2005
Reynolds averaging refers to the process of averaging a variable or an equation in time. Let be any dependent variable that varies in time. This variable can be decomposed into a fluctuating part, and an average part in the following way:

(1) 

Where is a long enough time to average out the fluctuations in .
Reynolds averaging is often used in fluid dynamics to separate turbulent fluctuations from the meanflow. The term Reynolds averaging originates from Osborne Reynolds, who was the first to use this type of averaging in fluid dynamics.