CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   Relation between Eulerian/Lagrangian and Kolmogorov time scales (http://www.cfd-online.com/Forums/main/96053-relation-between-eulerian-lagrangian-kolmogorov-time-scales.html)

zedik January 11, 2012 07:50

Relation between Eulerian/Lagrangian and Kolmogorov time scales
 
2 Attachment(s)
Hello everybody!

Does anybody know what is a Relation between Eulerian/Lagrangian and Kolmogorov time scales in turbulent flow?

>>> Kolmogorov scales:
'The flow consists of a spectrum of different scales (eddy sizes) where largest eddies are of the order of the flow geometry (i.e. boundary layer thickness, jet width, etc). At the other end of the spectra we have the smallest eddies which are by viscous forces (stresses) dissipated into internal energy'

Attachment 10792

>>> Eulerian time scales:
'Lagrangian time scale can be obtained by auto-correlating the velocity fluctuations of a fluid'

Attachment 10793

From those quates I understand physical meaning of kolmogorov scales. BUT what is the physical meaning for Eulerian/Lagrangian time scales ??

Does Eulerian time scale relate to kinetic energy dissipation ? How ?
How to measure those quantities in an experiment ?

What is the simplest way to model it numerically ?

Thanks a lot in advance !


All times are GMT -4. The time now is 18:56.