Periodic BC with Pyrosim

[gabferrara]

Hello everybody.
I was trying to make Pyrosim reading an .FDS file with the following vent specification:

&VENT MB=''XMIN'', SURF_ID=''PERIODIC'' /

Pyrosim is telling me that an error occurs:
"Invalid vent record specified.
The SURF, PERIODIC, does not exist in the Model"

Is there another way to accomplish this vent creation with Pyrosim?
I thank you in advance.

Gabriele

[Charlie Thornton]

PyroSim does not support the PERIODIC boundary condition option.  My understanding was that it was a feature used for internal testing by the developers:

http://groups.google.com/group/fds-smv/browse_thread/thread/47169114a71aec38/860008ee867d9e47

You can copy the &VENT record into the additional records section of the Record View to add the record if you''d just like to get it in there.  What sort of model are you working on?  (i.e. is there a case for PERIODIC outside V&V work?)

[gabferrara]

Hi.
Thank you for your reply.
I was trying to realistically model the atmospheric turbulence.
I read somewhere (I will send you soon the reference) that turbulence (or at least its effects) can be modelled by esplicitily modelling the atmospheric flow meandering (that is the periodic fluctuation of the wind velocity). I''m going to find the relevant paper and I''ll be more precise for this.
Regards.

Gabriele

[gabferrara]

Hello.

I''m trying to set up a periodic wind field in the domain.
The paper from Mouilleau and Champassith (Journal Loss Prevention Process Industries, 22, 2009, 169-176) state that this is necessary in order to get atmospheric dispersion properly simulated by FDS.
The paper is not very explicit about how to implement that but I will follow your indication and give a try.
I thank you again.

Gabriele

[Charlie Thornton]

Thanks for letting me know what you''re working on.  To be honest, I wasn''t too sure about what PERIODIC did -- the documentation is a bit indirect at this point.  Good luck with your model. 

The additional records section works well for anything that doesn''t need to be referenced by some other part of the model and VENT records are an ideal application.

[ksmujumdar]

Hello gabferrara,

Did you had further success with your Dispersion modeling using Pyrosim.

Thanks,

Regards
Kaustubh

[gabferrara]

Hi Kaustubh.

Sorry for this very delayed reply.
I have not logged in for a while.
No, I have not tried further in modelling dispersion with Pyrosim.
Can I suggest you reading a paper where success is claimed by authors in modelling atmospheric dispersion by means of pyrosim-fds:
"F. Gavelli, LES of LNG Vapor Dispersion".
Please let me know if you want me to send you a copy of it.
Regards

Gabriele