[raunakjung]

I am trying to carry out LES simulation in CFX. I see that fully developed inlet boundary conditions is an important aspect of it.
How to get fully developed inlet boundary conditions? Also what is a fully periodic solution.


Also, CFX guide gives following for initialization. When we initialize transient solution by previous RANS solution is it required to apply velocity fluctuation?
LES Initialization

For simulations initialized with values (rather than from an initial guess field), it is possible to perturb the initial guess by setting an RMS Velocity Fluctuation. This has the effect of kickstarting the solution process. For a velocity distribution, the fluctuation is the quantity:




The behavior of the velocity fluctuation is applied according to the following rules when you select Automatic or Automatic with Value as the Initialization option, as well as specify a velocity fluctuation:

If an initial values file is not found, the fluctuation is applied to the initial velocity field.

When an initial values file is used, it is assumed that you are restarting from a previous set of results, and the fluctuation is not applied.

If you want to apply a velocity fluctuation on a restart (for example, if the initial guess is a RANS solution), you can override this behavior by setting the expert parameter apply ic fluctuations for les to t.


Thank You