Preferred LES model for flows around an immersed body

[airwarriorg91]

Hello,
I planning to do LES for flows around immersed body for e.g. a flow around a sphere. Some reference articles use Dynamic Smagorinsky Model. Is the recommended ILES model suitable for such flows ?

I understand for enabling the ILES model, we need to set

ilesmod = 1
jles = 4
smagcst = 0.14

Do we need to set any other parameter for the use of ILES for the required flow ?

Thanks
Gaurav

[slaizet]

Hi Gaurav,
We advise our user to use ILES instead of explicit LES models (explicit LES models in Xcompact3d are only implemented for comparison purposes). As explained in our publications, our ILES approach relies on two parameters:

! Dissipation control for ILES when ilesmod=1 and jLES=4
nu0nu = 63             ! Ratio between hyperviscosity/viscosity at nu
cnu = 0.22               ! Ratio between hypervisvosity at k_m=2/3pi and k_c= pi

nu0nu is the amount of dissipation at the cut off wavenumber and cnu is the parameter to decide from which wavenumber you want to add numerical dissipation. I suggest you have a read at our publication on our ILES method and you can get familiar with the ILES with the TGV case, see input_ILES_Re5000.i3d.

Best,

Sylvain

[airwarriorg91]

Thanks for the answer ! This satisfies my query.