Taming the flame?


I have a fire sim that I set up. First 100 frames of the sim is pretty good for what I need but after around frame 120 (or the first 5 secs) it goes nuts ( see the video below). The flame and the burning rate almost starts accelerating suddenly. I am guessing that it is due to the temperature in the domain increasing.

I tried couple things including animating the time scale with small success. The flame rate still increases steadily while the time scale is animated to go down over time.

Is there a workaround the keep the fire “cool” as in the beginning? I guess what I need is to be abe to keep the fire time and the fuel burning rate to steady for about 1000 frames.




once encountered such issue, then i dropped the project and used stock fire elements. this post seems to be get answered. buddy just hopping in to get the answers. dont mind me. thanks

Thanks but that solution does not work because this fire has to be confined in a certain shape.

I’m not very deep into simu, but as you suggest the temperatur… Idea: Maybe increase the sim domain to have more air/space… if you know what i mean ?

I see something similar using the Quick Effects on sphere when I lower the CFL Number. It’s starts off slow, then speeds up. Try returning that number to default, or rebuild your setup and leave most settings alone.

The CFL value is at default already. I updated my post with the settings screnshots.

I am using the inflow model and a particles system as the source.

I get something similar, even without using your settings. This setup is being driven by particles. It’s like there is an accumulation on a value somewhere in the code that should be reset every frame.

Using Blender 3.0 Alpha.

If you are really running time ten times slower, you might want to add more substeps.

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Yes, that is what I am having in my setup too, and I have been suspecting that it is something to do with particle as a flow source.

I will try more substeps, but I doubt that it will address the real issue of accelerated fire generation.