DES in fluent 6.1.18??????????????
 

Hi evry body, How to introduce DES with Fluent 6.1.18? I have activat Spalart-Allmaras but I don't find turbulence- expert in the panel of viscous models (like it is say in the user guide)!!!

thanks

Re: DES in fluent 6.1.18??????????????
 

Dear naus,

You won't find this option in the menus. In Fluent 6.1.22 You have to choose 3d unsteady simulation, the spalart-allmaras model and then you must write in the prompt line:

/define/models/viscous/turbulence-expert/detached-eddy-simulation?

The program will ask you an answer (yes/no?).

Answer yes and detached eddy simulation will be selected. But I don't know if this trick is going to work in 6.1.18.

In case it works, there is a detail that is unknown to many users: in this version of fluent, when DES is selected the program applies the boundary conditions for turbulence fluctuations that are the default for LES, and are pretty high. So, you have a very high level of noise in the simulation. Before selecting the spalart-allmaras model is advisable to select LES and change the inlet boundary conditions for the tubulence fluctuations. Only then you should select spalart-allmaras and activate DES from the prompt line.

Regards,

Fabio