[rajnarayang]

Why is it that I can't see Kelvin Helmholtz vortex roll up in RANS analysis of round jets ( seen in LES) but can see Karman Vortex Street in the RANS simulations ??

[FMDenaro]

Originally Posted by rajnarayang

Why is it that I can't see Kelvin Helmholtz vortex roll up in RANS analysis of round jets ( seen in LES) but can see Karman Vortex Street in the RANS simulations ??

in RANS you can only solve the statistically steady fields

[rajnarayang]

Originally Posted by FMDenaro

in RANS you can only solve the statistically steady fields

So, is the Karman Vortex Street steady??

[FMDenaro]

The K-H vortices are alternate so they cannot be steady in deterministic sense but only in statistical sense. As a result you see only two steady separated symmetric region.