Dear All, Who can tell me what's the meaning of "rms-fluctuation velocity"? what's the physical meaning of it? How to compute it? thanks!

Hi,

the "rms-fluctuation velocity" is defined as : u'=sqrt{ M(u^2) - [M(u)]^2 }, where M is an average operator (time averaging, and space averaging if there are homogeneous flow directions). From a statistical point of view, this is the standard deviation of the random variable u. From a physical point of view, this may be related to the intensity of the turbulence. For example, the turbulent kinetic energy is classically defined as : k=.5(u'^2+v'^2+w'^2)

best regards