# how to get Root Mean Square (RMS) velocity

hello,

I'm doing cavitation simulation using LES turbulent model.

In the Fluent, we can plot the graphic of RMSE velocity magnitude (not only velocity but also for other parameters) base on the sampled LES results. However, as I checked, RMSE and RMS are two different concepts.

I checked the ANSYS Fluent Theory Guide. I only find RMS in instead of RMSE. Therefore, I am confused. Is RMSE in Fluent is the root mean square error of velocity or root mean square of velocity?

Thank you.

## Answers

Root Mean Square Error of X Velocity is actually what we understand under SQRT(mean(u'^2))

How to obtain u' in LES fluent ?

Thank you for advance

That is what I posted RMSE X, Y and Z velocity. If you want to have another definition you will then build up your own variable.