Modeling the Ventilation Resistance of an Intumescent Material under Heating

[JUNPSE7]

I am working on modeling an intumescent material that is used in doors and similar assemblies to block flames and hot gases leaking through gaps during a fire. This material expands with increasing temperature and seals the gap to provide a fire barrier.

Specifically, I would like to know how to represent the ventilation resistance of this expanding material as a function of temperature in FDS. I plan to measure the temperature-dependent expansion and airflow resistance through experiments separately.

Could you please advise on how to model this behavior in FDS? If there are any example cases or recommended approaches (e.g., using HVAC components, OBST updates, or other methods), I would really appreciate it.

Thank you in advance!

[drjfloyd]

If I were going to try and model this I think I would use HVAC for the leakge paths and do a ramp for the duct loss that used temperature as the independent variable. This is not a specific application that I am aware anyone has done before so I can't tell you specifically how to do this.

[JUNPSE7]

Thank you Jason for your reply.
Using HVAC with a temperature-dependent duct loss ramp sounds like a practical approach, especially since it can approximate the increasing resistance as the material expands.

I’ll try implementing this using the TABLE function for duct loss. If I encounter issues during the setup, I might come back with some follow-up questions.

Much appreciated for your guidance!