Question on Setting SEM Parameters in FDS

[HEROISCOMING1]

Hello,
I am currently studying microscale meteorological simulations using FDS, and I have a question I hope you can help with.

I’m trying to maintain turbulence at the LES model boundary by using the Synthetic Eddy Method (SEM). Based on the user guide and other references, I understand that the options N_EDDY, L_EDDY, and VEL_RMS should be manually specified.

N_EDDY: Number of eddies

L_EDDY: Distance over which eddies are blended into the mean flow

VEL_RMS: Root-mean-square of the eddy velocity

My question is: how should I determine appropriate values for these parameters?

For example, if I'm simulating an atmospheric condition with a mean wind speed of 1.0 m/s, using a time step of 1 second and a total simulation time of 600 seconds, how should I choose the values for these SEM parameters?

[mcgratta]

There is a paper referenced in the guide. Have you checked that?

[HEROISCOMING1]

I have reviewed the relevant papers, but I have not been able to find a clear answer on how to apply the three options above (such as N_EDDY, L_EDDY, and VEL_RMS) to an LES model that considers actual atmospheric conditions.

[mcgratta]

Look at the sample cases called Turbulence/sem_...fds