[sibo]

Hi Hasan,

I'm wondering did you find the answer? I am facing a similar problem in which the RANS content is about 90%. And I'm using SA-DDES which should only apply RANS in the near wall region where d < C_DES*delta.

Thanks in Advance!

Sibo

[samik108]

Originally Posted by Alhasan

Dear All,

I am trying to run a IDDES simulation, well it seems to be running without any issues but the only problem I can find is the

# DES model region coverage (% volume)
# time     LES    RAS
0.353574    8.77114    91.2289
0.353578    8.76998    91.23
0.353581    8.76933    91.2307
0.353585    8.7692    91.2308
0.353589    8.76834    91.2317
0.353593    8.76737    91.2326
0.353596    8.76641    91.2336

That LES percentage is so less compared to the RANS, how can I resolve this issue ? any ideas ?

- I ran a URANS simulation and used one of the very well last converged time step to start this simulation !!! say 0.3576 time step

Would it be starting the simulation with the first time step of URANS making it more of a RANS simulation or something ?

What could be happening here, from what I know the RANS is suposed to be only close to the walls of the simulation and not the entire domain for IDDES,

This is my first IDDES simulation so please explain well,

Thanks for your time and effort,

Edit:
If the post here hasnt given enough information, I have also posted a similar question here http://www.cfd-online.com/Forums/ope...tml#post577568

Kind Regards,
Hasan K.J

hello, for des you need special kind of meshing refinement only in leeward, wake side and transverse direction not in windward side. You should not refine mesh nearwall region much.