Thunderhead Engineering Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Forum moved to https://forum.thunderheadeng.com

Author Topic: Curtains in PyroSim  (Read 747 times)

maryl

  • New Member
  • *
  • Posts: 1
    • View Profile
Curtains in PyroSim
« on: May 05, 2018, 01:38:24 am »

Hi!

I wonder how to make curtains in PyroSim.

I have tried to make it as a thin obstruction, but it doesn't work to add surfaces made by me, with specified thermal properties. I have also tried to make it as a normal obstruction, but then they have to be too thick.

Thank you!
Logged

jharbold

  • Member
  • **
  • Posts: 26
    • View Profile
Re: Curtains in PyroSim
« Reply #1 on: May 05, 2018, 03:06:22 pm »

It appears that you have stumbled upon a problem which may require a unique solution from you.  Including a thin curtain as you desire isn't inherently "too thick", but your mesh likely is.  You would have to reduce your mesh size down so that your curtains are able to be the correct thickness.  To make matters worse, there are studies on FDS and burning of materials which, if I recall correctly, say that a minimum of 10 mesh thicknesses in a material is required to accurately simulate the burn (a sensitivity analysis in comparison to experimental results could allow you to define this for your scenario).  Going this route, the mesh that you use would have to be so small that the simulation is likely not able to be run in a feasible amount of time.

Your other option would be to perform less of a "true simulation" and use a different method.  If you know what the material temperature is, you could perhaps place several temperature devices at the location where the material is located.  Then, link a burner with a predefined HRR and growth profile to activate when any of those devices is activated.

Finally, maybe some reconsideration is necessary for the simulation as a whole.  Are curtains a significant part of the fuel package that is available in this simulation?  The FDS model is never going to be perfect - is including these curtains going to make it more realistic or just muddy the waters on understanding whether or not your outputs are valuable based on your inputs.
Logged