URANS and Reynolds stress
 

Hello guys, regarding the Reynolds stress, we have the following ways to calculate it in OpenFOAM:

1) for LES, we can obtain the resolved Reynolds stress by UPrime2Mean.
2) for RANS, we can obtain the Reynolds stress by postProcess -R function.

But what about URANS? Is it identical with RANS? Lets take the flow over cylinder as an example, in such flows, R is also periodic, In order to obtain averaged Reynolds stress, we also need to calculate time-averaged R?

Affermative, yes, true, the tensor R at every time step is a Reynolds averaged quantity.