How to create a new reaction (outside the default library) in PyroSim.

[Mohammadndi]

I want to add a new custom reaction that is not available in the PyroSim library. However, I can't do it because PyroSim only recognizes gaseous species containing C, H, O, and S. But I need to input the combustion reaction of black powder:

2 KNO₃ + S + 3 C → K₂S + N₂ + 3 CO₂

In this reaction, KNO₃ is a solid, and I don’t know how to define this as a new reaction. Whatever I try results in an error.
I would appreciate it if you could help me.

[drjfloyd]

Have you tried reading the FDS User's Guide?

[Mohammadndi]

Yes در تاریخ شنبه ۲ اوت ۲۰۲۵،‏ ۱۴:۳۸ Jason Floyd ***@***.***> نوشت:

…

Have you tried reading the FDS User's Guide? — Reply to this email directly, view it on GitHub <#14917 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BVOSIFMH3QYAHLN3G6HSEF33LSE2PAVCNFSM6AAAAACC6IZ2QCVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGOJWHA2TKNI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[Mohammadndi]

Yes

[drjfloyd]

Then if you cannot figure out Pyrosim (with the help of Thunderhead Engineering as this is not a Pyrosim forum), you can edit your fds file by hand following the detailed examples of reactions containing elements other than C,H,O, and N that can be found in the FDS User's Guide.