SEM with uRANs

[st268]

Hello,

Is there anything stopping me using the Synthetic Eddy Method boundary conditions with uRANs turbulence and suitable timestep/grid sizings?

Susan

[Brian Angel]

Hello Susan,

A priori you cannot but I'd like to look into the source code before giving a definitive answer. I'll let you know what I find out.

Just one question, why do you want to use the SEM method with URANS?

Regards,

Brian Angel.

[Brian Angel]

Hello Susan,

I have looked through the Code_Saturne source files and there does not appear to be anything stopping you from setting up the SEM inputs files in the SRC directory. However, whether the RANS turbulence model that you are using will subsequently use what is calculated by the SEM remains doubtful given that this method is intended for use with the LES method.

Can you let me know why you want to use the SEM in your unsteady RANS simulation.

Brian Angel.

[st268]

Hello Brian,

Thank you for checking for me.

It is a bit of an experiment really. I am interested in large scale eddies and would like to investigate just how much of these I can resolve with uRANs by playing around. I know SEM is usually used with LES but if I can get it working with uRANS it would greatly reduce the cost of my simulations.

And that is where my real reason comes in - I do not want to have to switch up to LES! I will see what I can get working and let you know if you are interested?

cheers

Susan

[Brian Angel]

Hello Susan,

Thanks for letting me know why you want to use the SEM. Yes, I would be interested in knowing if you can get it working with URANS so please keep me posted. If you need to modify the CS source code, the CS routines that are of interest are:

base directory:
caltri.f90
condli.f90
tridim.f90

apps directory
cs_solver.c

turb directory:
cs_les_inflow.c

(there might be others so please look) plus the user routines that specify inputs for the SEM.

Brian.

[st268]

Hi Brian,

Just to let you know that SEM is working fine with uRANS. In fact no extra effort was required on my part over using it with LES. I am still investigating how far I can go with it as an alternative to LES but there are no issues with getting it running in the first place

thanks

Susan